Answer:
The answer is 10
Step-by-step explanation:
The value of f(5) will be 10 for the given sequence.
What is Sequence?A grouping of two or more items in a logical sequence. the sequential arrangement of two or more items. The sequence is a term used to describe chronological order. You should be familiar with the following four primary categories of sequences: arithmetic sequences, geometric sequences, quadratic sequences, and special sequences. a collection of two or more elements arranged logically. the placement of two or more elements in a particular order. The word "sequence" refers to chronological order. Arithmetic sequences, geometric sequences, quadratic sequences, and special sequences are the four main types of sequences that you should be aware of.
Given, A sequence is defined by the recursive formula f (n + 1) = f(n) – 2. If f(1) = 18.
for n = 1
f(2) = f(1) - 2 = 18 -2 = 16
for n = 2
f(3) = f(2) - 2 = 16 - 2 = 14
for n = 3
f(4) = f(3) - 2 = 14- 2 = 12
for n = 4
f(5) = f(4) - 2 = 12-2 = 10
Therefore, For the above sequence, f(5) will have the value of 10.
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Question 5 of 8 2 Points Which values are solutions to the inequality below? Check all that apply. x2 > 10
A. -2
B. 3
C. 4
D. -4
Answer:
4 and -4
Step-by-step explanation:
> means greater than
x² > 10
4² > 10 → True, 16 is greater than 10
-4² > 10 → True, 16 is greater than 10
A line in the Cartesian plane passes through the points (5,8) and (9,15). What is the slope of the line?
A. 4⁄7
B. –7⁄4
C. –4⁄7
D. 7⁄4
[tex]\bf (\stackrel{x_1}{5}~,~\stackrel{y_1}{8})\qquad (\stackrel{x_2}{9}~,~\stackrel{y_2}{15}) \\\\\\ slope = m\implies \cfrac{\stackrel{rise}{ y_2- y_1}}{\stackrel{run}{ x_2- x_1}}\implies \cfrac{15-8}{9-5}\implies \cfrac{7}{4}[/tex]
The cost, in dollars, for a doll company to produce x number of dolls is given by the function below. Which statement best describes the minimum cost of production for the company? The minimum cost of production is $260 for 70 dolls. The minimum cost of production is $35 for 383 dolls. The minimum cost of production is $383 for 35 dolls. The minimum cost of production is $70 for 260 dolls.
Final answer:
The minimum cost of production for the company is $260 for 70 dolls.
Explanation:
The minimum cost of production for the company can be determined by examining the options given. The correct statement is:
The minimum cost of production is $260 for 70 dolls.
In the given function, the cost of production is represented by the variable x. The equation cost = 50 + 10x describes the cost of producing x number of dolls. By substituting x with 70 in the equation, we can calculate the cost as follows:
Cost = 50 + 10 * 70 = 50 + 700 = $750
Therefore, the minimum cost of production for the company is $260 for 70 dolls.
A gym surveyed 100 female members. These members were chosen at random from the gym's membership database. Participants were asked the question, "Do you prefer to use the easy weight-lifting machines or the harder free weights?"
A report of the survey results stated that female members at the gym prefer the weight-lifting machines over the free weights.
Select ALL statements that correctly evaluate the report.
Answer:
Step-by-step explanation:
The sample is not biased. The members were selected at random from the gym's female population.
The question is biased. It described the weight lifting machines as "easy" and the free weights as "harder".
The second and third choices are correct.
Can you guys please help
if you add 3 to it it would be 6
Which inequality statement best represents the graph?
f(x) > –x2 + x – 1
f(x) < x2 + x – 1
f(x) < –x2 + x – 1
f(x) > x2 + x – 1
Answer:
f(x) < –x2 + x – 1
Step-by-step explanation:
The graph is going down so we know that there is a maximum, therefore the A value has to be negative. This rules out f(x) < x2 + x – 1 and f(x) > x2 + x – 1 . The shaded area of the graph is below which indicates that f(x) has to be less than the function. This means the correct answer is f(x) < –x2 + x – 1 .
Answer:
[tex]y>-x^2 +x-1[/tex]
Step-by-step explanation:
Lets find the inequality that best describes the given statement
The graph of the parabola is upside down so the value of 'a' is -1
It means the equation for the parabola becomes [tex]y=-x^2 +x-1[/tex]
Now to get inequality , lets pick a point from the shaded part .
Lets pick (0,0), plug in 0 for x and 0 for y
[tex]y=-x^2 +x-1[/tex]
[tex]0=-(0)^2 +(0)-1[/tex]
[tex]0=-1[/tex]
0 is greater than -1
[tex]y>-x^2 +x-1[/tex]
Select the correct answer from each drop-down menu. The equation (y-2)^2/3^2 - (x-2)^2/4^2=1 represents a hyperbola whose foci are blank and blank .
Answer:
The foci are (2 , 7) and (2 , -3)
Step-by-step explanation:
* lets revise the equation of the hyperbola
- The standard form of the equation of a hyperbola with
center (h , k) and transverse axis parallel to the y-axis is
(y - k)²/a² - (x - h)²/b² = 1
- The coordinates of the vertices are ( h ± a , k )
- The coordinates of the co-vertices are ( h , k ± b )
- The coordinates of the foci are (h , k ± c), where c² = a² + b²
* Now lets solve the problem
∵ The equation of the hyperbola of vertex (h , k) is
(y - k)²/a² - (x - h)²/b² = 1
∵ The equation is (y - 2)²/3² - (x - 2)²/4² = 1
∴ k = 2 , h = 2 , a = 3 , b = 4
∵ The foci of it are (h , k + c) and (h , k - c)
- Lets find c from the equation c² = a² + b²
∵ a = 3
∴ a² = 3² = 9
∵ b = 4
∴ b² = 4² = 16
∴ c² = 9 + 16 = 25
∴ c = √25 = 5
- Lets find the foci
∵ The foci are (h , k + c) and (h , k - c)
∵ h = 2 , k = 2 , c = 5
∴ The foci are (2 , 2 + 5) and (2 , 2 - 5)
∴ The foci are (2 , 7) and (2 , -3)
Answer:
The foci are (2 , 7) and (2 , -3)
Step-by-step explanation:
Solve the inequality. SHOW YOUR WORK.
–6b > 36 or 2b > –4
**WHOEVER SHOWS THEIR WORK AND IS CORRECT WILL BE MARKED AS BRAINLEST**
-6b > 36
Divide both sides by -6;The result is b!b > -6or 2b > -4Divide both sides by 2The result is b!b > -2use a cube and a cylinder to build a new shape. Repeat. Draw to show how you can combine these two new shapes to make a larger shape
Check the picture below.
If these two shapes are combined then the new shape is generated. Then the new shape will be given below.
What is Geometry?It deals with the size of geometry, region, and density of the different forms both 2D and 3D.
A cube and a cylinder are given.
If these two shapes are combined then the new shape is generated. Then the new shape will be
The shape is given below.
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What is the tangent ratio for ∠A?
Answer:
Tan <A = 1/2
Step-by-step explanation:
SOH CAH TOA
TOA (opposite/adjacent)
So, the answer is 1/2
because the opposite of <A is 1 and the adjacent is 2.
For this case we have to define trigonometric relations of rectangular triangles, that the tangent of an angle is given by the leg opposite the angle on the leg adjacent to the angle. Then, according to the figure we have:
[tex]tg (A) = \frac {1} {2}[/tex]
Answer:
[tex]tg (A) = \frac {1} {2}[/tex]
A number generator was used to simulate the percentage of people in a town who ride a bike. The process simulates randomly selecting 100 people from the town and was repeated 20 times. The percentage of people who ride a bike is shown in the dot plot.
Which statement is true about the population of the town?
Answer:
Step-by-step explanation:
Of the 20 trials, 18 of them ended up between 60 and 75. So most likely, 60% to 75% of the town rides a bike.
The true statement about the dot plot is (c) Most likely, 60% to 75% of the town rides a bike.
How to interpret the dot plot?From the dot plot, we have the following sample between 60 and 75%
Sample = 3 + 4 + 6 + 5
Evaluate
Sample = 18
The above means that 18 out of the 20 trials fall between 60 and 75%
This means that between 60 and 75% of the town rides a bike
Hence, the true statement about the dot plot is (c)
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zoes living room rug is 3 feet wide and 7 feet long she will cover the rug with 6 inch cardboard pieces for a painting project how many cardboard pieces will zoe need
Zoe will need 84 pieces if they are 6” by 6”
For this case we have that by definition, 1 foot equals 12 inches.
So:
[tex]3 \ ft = 36 \ in\\7 \ ft = 84 \ in[/tex]
So, the area of the Zoes carpet is:
[tex]A = 36 * 84 = 3024 \ in ^ 2[/tex]
If the cardboard pieces are[tex]6 \ in\ by\ 6 \ in[/tex], then the area is:
[tex]36 \ in ^ 2[/tex]
To indicate the number of necessary pieces we divide:
[tex]\frac {3024} {36} = 84[/tex]
Thus, 84 pieces of cardboard are needed
Answer:
84
There are 11 paintings at an art show. Four of them are chosen randomly to display in the gallery window. The order in which they are chosen does not matter. How many ways are there to choose paintings? A. 7920 B. 330 C.44 D. 121
Answer:
B. 330
Step-by-step explanation:
The question indicates the order doesn't matter, so it's a combination and not a permutation.
The combinations are calculated using this formula:
[tex]C(n,r) = \frac{n!}{r! (n-r)!}[/tex]
In this case we have a population of 11 (n = 11) and a selection of 4 (r=4), so...
[tex]C(11,4) = \frac{11!}{4! (11-4)!} = 330[/tex]
So, there are 330 different combinations that can be made of 4 paintings out of a selection of 11.
Answer:
The correct answer is option B. 330
Step-by-step explanation:
It is given that,There are 11 paintings at an art show. Four of them are chosen randomly to display in the gallery window.
To find the possible ways
There are total 11 paintings.
We have to choose 4 of them
Possible number of ways = 11C₄
= (11 * 10 * 9 )/(1 * 2* 3 * 4)
= 330 ways
Therefore the correct answer is option B. 330
What is the answer and why?
Answer:
g(10) is undefined
Step-by-step explanation:
A vertical asymptote is a place where a function is literally undefined. That is commonly because the function is a rational function with a denominator of zero at that point (division by zero is undefined), but it can also be for any of a variety of other reasons.
Find m angle T, rounded to the nearest degree
Answer: First option.
Step-by-step explanation:
You can use the inverse tangent function to find the value of the angle T:
[tex]\alpha=arctan(\frac{opposite}{adjacent})[/tex]
You can identify in the figure that:
[tex]\alpha=T\\opposite=RG=8\\adjacent=TR=15[/tex]
Then, knowing these values, you can substitute them into [tex]\alpha=arctan(\frac{opposite}{adjacent})[/tex].
Therefore, you get that the value of the angle T rounded to the nearest degree is:
[tex]T=arctan(\frac{8}{15})\\\\T=28\°[/tex]
This matches with the first option.
Suppose the initial height of a Pumpkin is 12 feet and the pumpkin is being launched with a velocity of 61 feet per second. Use this information to find out the maximum height the pumpkin will go before landing.
Please show your work
(98 points)
The answer is:
The maximum height before landing will be 69.7804 feet.
Why?Since there is no information about the angle of the launch, we can safely assume that it's launched vertically.
So, we can calculate the maximum height of the pumpkin using the following formulas:
[tex]y=y_o+v_{o}*t-\frac{1}{2}gt^{2}[/tex]
[tex]v=vo-gt[/tex]
Where,
y, is the final height
[tex]y_o[/tex], is the initial height
g, is the acceleration of gravity , and it's equal to:
[tex]g=32.2\frac{ft}{s^{2} }[/tex]
t, is the time.
Now, we are given the following information:
[tex]y_{o}=12ft\\\\v=61\frac{ft}{s}[/tex]
Then, to calculate the maximum height, we must remember that at the maximum height, the speed tends to 0, so, calculating we have:
Time calculation,
We need to use the following equation,
[tex]v=vo-gt[/tex]
So, substituting we have:
[tex]v=61\frac{ft}{s}-32.2\frac{ft}{s^{2}}*t\\\\-61\frac{ft}{s}=-32.2\frac{ft}{s^{2}}*t\\\\t=\frac{-61{ft}{s}}{-32.2\frac{ft}{s^{2}}}=1.8944s[/tex]
We know that it will take 1.8944 seconds to the pumpkin to reach its maximum height.
Maximum height calculation,
Now, calculating the maximum height, we need to use the following equation:
[tex]y=y_o+v_{o}*t-\frac{1}{2}gt^{2}[/tex]
Substituting and calculating, we have:
[tex]y=y_o+v_{o}*t-\frac{1}{2}gt^{2}[/tex]
[tex]y=12ft+61\frac{ft}{s}*1.8944s-\frac{1}{2}32.2\frac{ft}{s^{2}}*(1.8944s)^{2}[/tex]
[tex]y=12ft+61\frac{ft}{s}*1.8944s-\frac{1}{2}32.2\frac{ft}{s^{2}}*(1.8944s)^{2}\\\\y_{max}=12ft+115.5584ft-16.1\frac{ft}{s^{2}}*(3.5887s^{2})\\\\y_{max}=127.5584ft-57.7780ft=69.7804ft[/tex]
Hence, we have that the maximum height before the landing will be 69.7804 feet.
Have a nice day!
Evaluate 7 − (−1).
6
−6
8
−8
Simplify brackets
7 + 1
Simplify
8
Answer: C. 8
Answer:
minus and minus is plus
7+ 1 is 8 :)
rewrite the equation in Ax + By = C.
use integers for A, B, and C.
y= - 1/2 x - 4
Answer:
1/2x+y=-4
Step-by-step explanation:
Answer:
x + 3y = - 8
Step-by-step explanation:
Given
y = - [tex]\frac{1}{2}[/tex] x - 4
Multiply all terms by 2
2y = - x - 8 ( add y to both sides )
x + 2y = - 8 ← in standard form
Please answer this multiple choice question CORRECTLY for 30 points and brainliest!!
Answer:
C.
Step-by-step explanation:
The mapping for 90° counterclockwise rotation is ...
(x, y) ⇒ (-y, x)
If we consider how this applies to points X and Y, which both have a y-coordinate of 0 and a negative x-coordinate, (-a, 0), for example, we see it maps to ...
(-a, 0) ⇒ (0, -a)
That is, both points X' and Y' will be on the negative y-axis. The only figure showing this is figure C.
______
Comment on the other answer choices
Figures A and D show clockwise rotation. In Figures A and B, the rotation is not about the origin, but is about a different point. (In Figure B, the points easy to consider are the ones on the -x axis, points X and Z. They should appear on the -y axis after rotation, but do not.)
Which of the following are true statemetns about a 30-60-90 triangle?
I think it is a and b but I'm not sure
Answer:
Use the hyper link
Step-by-step explanation:
I took a picture on the unit.
Answer:
A.The longer leg is √3 times as long as the shorter
B. The hypotenuse is twice as long as the shorter leg
Step-by-step explanation:
The 30-60-90 is a special triangle with two acute angles 30° and 60°
The side across from the 30°= shorter leg
The side across from 60°=longer leg
The side across from 90°=hypotenuse
If we take the shorter side to be x and hypotenuse to be 2x then the longer leg will be;
Apply Pythagorean relationship
a² + b² =c²
c²-a²=b² where-----------c=2x and a=x
(2x)² - x² = b²
4x² - x² =b²
3x² = b²
√3x²=b
x√3 =b
Hence longer leg is √3 times longer than the shorter leg which is x and the hypothenuse 2x is twice the shorter leg which is x
Graph the solution set of the system of inequalities or indicate that the system has no solution.
y ≥ 2x – 4
x + 2y ≤ 7
y ≥ -2
x ≤ 1
The graph of inequality have many solution .
What is graph of inequality?The graph of an inequality in two variables is the set of points that represents all solutions to the inequality. A linear inequality divides the coordinate plane into two halves by a boundary line where one half represents the solutions of the inequality. The boundary line is dashed for > and < and solid for ≤ and ≥.If the symbol ≥ or > is used, shade above the line. If the symbol ≤ or < is used shade below the line.
According to the question
The system of inequalities:
y ≥ 2x – 4
x + 2y ≤ 7
y ≥ -2
x ≤ 1
values to the graph of inequalities we will have to make inequalities into equal sign
y ≥ 2x – 4
y = 2x – 4
x y
0 -4
1 -2
2 0
Now,
As per graph of inequalities rules:
The solid line for ≤ and ≥.If the symbol ≥ or > is used, shade above the line.
x + 2y ≤ 7
x + 2y = 7
x y
0 3.5
1 3
2 2.5
Now,
As per graph of inequalities rules:
The solid line for ≤ and ≥.If the symbol ≤ or < is used, shade below the line.
y ≥ -2
y = -2
Now,
As per graph of inequalities rules:
The solid line for ≤ and ≥.If the symbol ≥ or > is used, shade above the line.
x ≤ 1
x = 1
Now,
As per graph of inequalities rules:
The solid line for ≤ and ≥.If the symbol ≤ or < is used, shade below the line.
Therefore, the darker part in graph is common part of all 4 inequalities with point (1,-2) and (1,3) .
Hence, The graph of inequality have many solution .
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What is the length of a line segment on the coordinate plane with end point (3,5) and (6,8) to the nearest tenth
Answer:
Step-by-step explanation:
Use the distance formula for coordinate geoemetry and the fact that x1 = 3, y1 = 5, x2 = 6 and y2 = 8 to fill in the formula:
[tex]d=\sqrt{(x_{2}-x_{1})^2+(y_{2}-y_{1})^2 }[/tex]
fills in accordingly:
[tex]d=\sqrt{(6-3)^2+(8-5)^2}[/tex]
which simplifies a bit to
[tex]d=\sqrt{(3)^2+(3)^2}[/tex]
which is
[tex]d=\sqrt{18}[/tex]
The square root of 18 simplifies down to [tex]3\sqrt{2}[/tex], which is 4.2426 in decimal form
Answer:
4.24 units
Step-by-step explanation:
We can use the distance formula to solve this.
Distance formula: d = √((x₁ - x₂)² + (y₁ - y₂)²), where (x₁, y₁) and (x₂, y₂) are the two coordinates.
Plug in: d = √((3 - 6)² + (5 - 8)²)
Subtract: d = √((-3)² + (-3)²))
Square: d = √(9 + 9)
Add: d = √18
Square root: d = 4.24264... ≈ 4.24 units
Solve the system of equations given below
[tex]
y-15=3x \\
-2x+5y=-3 \\ \\
-2x+y-15=0 /\cdot2 \\
-2x+5y-3=0 /\cdot(-2) \\ \\
-4x+2y-30=0 \\
4x-10y+6=0 \\ \\
-8y-24=0 \\
\boxed{y=-3} \\ \\
-3-15=3x \\
\boxed{x=-6}
[/tex]
The answer is C. (-6, -3)
Hope this helps.
r3t40
For this case we have the following system of equations:
[tex]y-15 = 3x\\-2x + 5y = -3[/tex]
We multiply the first equation by -5:
[tex]-5y + 75 = -15x[/tex]
Now we add the equations:
[tex]-2x-5y + 5y + 75 = -3-15x\\-2x + 75 = -3-15x\\-2x + 15x = -75-3\\13x = -78\\x = \frac {-78} {13}\\x = -6[/tex]
We find the value of the variable "y" according to the first equation:
[tex]y = 3x + 15\\y = 3 (-6) +15\\y = -18 + 15\\y = -3[/tex]
The solution of the system is: (-6, -3)
Answer:
(-6, -3)
Option C
Jalen randomly chooses a number from 1 - 10 . What Is the probability he chooses a number greater than 3?
A. 3/5
B. 1/5
C. 7/9
D. 7/10
The answer will be D. 7/10 because you have 10 numbers and you want to have a number greater than 3 so it would be 10-3=7 and 7 would go over 10 because there are 7 numbers greater than 3 but less than 10.
The probability he chooses a number greater than 3 is 7/10, the correct option is D.
What is Probability?Probability is the likeliness of an event to happen.
Jalen randomly chooses a number 1-10
Probability = ( No. of favourable outcomes)/ Total Outcomes
The chances of getting the number more than 3 is 7
Total numbers are 10
The probability he chooses a number greater than 3 is 7/10.
Therefore, the correct option is D.
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Which value is not in the domain of the function?
Answer:
The answer is the second choice.
Step-by-step explanation:
The value of the domain which is not part of the function is x = -2.
Given data:
The domain of a function is the set of values that are allowed to plug into the function which are the inputs.
The domain of the three line segments is represented as:
Domain of line 1 ranges from [ -5 , -2 ).
Domain of line 2 ranges from ( -2 , 2 ).
Domain of line 3 ranges from [ 2 , 5 ].
So, the value -2 is not included in the domain values of the function.
Hence, x = -2 is not in the domain of function.
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solve for x and show all your work
3x + 4 = 16
Answer:
x=4
Step-by-step explanation:
16-4=12
3x=12
3*4=12
Answer: [tex]x=4[/tex]
Step-by-step explanation:
You need to find the value of the variable "x".
To solve for "x", the first step is to apply the Subtraction property of equality, which states that:
[tex]If\ a=b\ then\ a-c=b-c[/tex]
Then, you need to subtract 4 from both sides of the equation:
[tex]3x + 4 = 16\\3x + 4-4 = 16-4\\3x=12[/tex]
And finally, you can apply the Division property of equality, which states that:
[tex]If\ a=b\ then\ \frac{a}{c}=\frac{b}{c}[/tex]
Then you can divide both sides of the equation by 3, getting:
[tex]\frac{3x}{3}=\frac{12}{3}\\\\x=4[/tex]
For real number a, which of the following equations are true ? Select all that apply.
ANSWER
[tex] \lim_{x \to \: a}(x) = a[/tex]
[tex]\lim_{x \to \: a}(a) = a[/tex]
[tex]\lim_{x \to \: 5}(x) = 5[/tex]
EXPLANATION
For real number 'a',
[tex] \lim_{x \to \: a}(x) = a[/tex]
is true because we have to plug in 'a' for x.
[tex]\lim_{x \to \: a}(a) = a[/tex]
This is also true because limit of a constant is the constant.
[tex]\lim_{x \to \: 5}(4) = 5[/tex]
is false. The correct value is
[tex]\lim_{x \to \: 5}(4) =4[/tex]
[tex]\lim_{x \to \: 5}(x) = 5[/tex]
is also true because we have to substitute 5 for x.
[tex]\lim_{x \to \: a}(a) = x[/tex]
is also false
The limit should be
[tex]\lim_{x \to \: a}(a) = a[/tex]
Answer:
A, B, D
Step-by-step explanation:
Answers for the rest of the quick check
1. A,B,D
2. 16, D
3. 10a, B
4. 3, D
Good Luck :)
Decide if the function is an exponential growth function or exponential decay function, and describe its end behavior using limits. y=0.8^x
The given function y=0.8^x is an exponential decay function. It's end behavior is defined such that as x grows significantly large, y approaches 0, and as x becomes significantly negative, y approaches infinity.
Explanation:The function
[tex]y=0.8^x[/tex]represents exponential decay because the base (0.8) is between 0 and 1. When the base of the power function is in this range, it results in a decreasing or 'decay' function. This contrasts with an exponential growth function, where the base would be greater than 1.
Regarding the end behavior of this function, we can analyze it using the concept of limits. As x approaches positive infinity (x -> +∞), y will approach zero (y -> 0) because a fraction (0.8 in this case) to a large power tends to zero. This illustrates the decay aspect of the function. Conversely, as x approaches negative infinity (x -> -∞), y will approach positive infinity (y -> +∞).
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The function y = 0.8^x is an exponential decay function. As x increases, y decreases exponentially. The end behavior of the function is that it approaches 0 as x approaches positive and negative infinity.
Explanation:The function y = 0.8^x is an exponential decay function. In an exponential decay function, the base is between 0 and 1, and as x increases, y decreases exponentially. This function represents the decay of a quantity over time, where the quantity is decreasing by 20% for each unit increase in x.
Regarding the end behavior and limits, as x approaches positive and negative infinity, the function approaches 0. This means that the y-values get closer and closer to 0 as x becomes larger and smaller. In other words, the function approaches the x-axis but never reaches it.
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In right △ABC, the altitude CH to the hypotenuse AB intersects angle bisector AL in point D. Find the sides of △ABC if AD = 8 cm and DH = 4 cm.
Answer:
[tex]AC=8\sqrt{3}\ cm\\ \\AB=16\sqrt{3}\ cm\\ \\BC=24\ cm[/tex]
Step-by-step explanation:
Consider right triangle ADH ( it is right triangle, because CH is the altitude). In this triangle, the hypotenuse AD = 8 cm and the leg DH = 4 cm. If the leg is half of the hypotenuse, then the opposite to this leg angle is equal to 30°.
By the Pythagorean theorem,
[tex]AD^2=AH^2+DH^2\\ \\8^2=AH^2+4^2\\ \\AH^2=64-16=48\\ \\AH=\sqrt{48}=4\sqrt{3}\ cm[/tex]
AL is angle A bisector, then angle A is 60°. Use the angle's bisector property:
[tex]\dfrac{CA}{CD}=\dfrac{AH}{HD}\\ \\\dfrac{CA}{CD}=\dfrac{4\sqrt{3}}{4}=\sqrt{3}\Rightarrow CA=\sqrt{3}CD[/tex]
Consider right triangle CAH.By the Pythagorean theorem,
[tex]CA^2=CH^2+AH^2\\ \\(\sqrt{3}CD)^2=(CD+4)^2+(4\sqrt{3})^2\\ \\3CD^2=CD^2+8CD+16+48\\ \\2CD^2-8CD-64=0\\ \\CD^2-4CD-32=0\\ \\D=(-4)^2-4\cdot 1\cdot (-32)=16+128=144\\ \\CD_{1,2}=\dfrac{-(-4)\pm\sqrt{144}}{2\cdot 1}=\dfrac{4\pm 12}{2}=-4,\ 8[/tex]
The length cannot be negative, so CD=8 cm and
[tex]CA=\sqrt{3}CD=8\sqrt{3}\ cm[/tex]
In right triangle ABC, angle B = 90° - 60° = 30°, leg AC is opposite to 30°, and the hypotenuse AB is twice the leg AC. Hence,
[tex]AB=2CA=16\sqrt{3}\ cm[/tex]
By the Pythagorean theorem,
[tex]BC^2=AB^2-AC^2\\ \\BC^2=(16\sqrt{3})^2-(8\sqrt{3})^2=256\cdot 3-64\cdot 3=576\\ \\BC=24\ cm[/tex]
A firecracker shoots up from a hill 160 feet high, with an initial speed of 90 feet per second. Using the formula H(t) = −16t2 + vt + s, approximately how long will it take the firecracker to hit the ground?
A. Five seconds
B. Six seconds
C.Seven seconds
D.Eight seconds
H(t) = -16t² + vt + s
Where -16 is half of the gravitational constant of almost 32 ft/sec (downward, thus negative),
v is the initial velocity (90), and
s is the starting height (160)
so we have:
H(t) = -16t² + 90t + 160
How long before it hits the ground? Solve for h(t) = 0:
0 = -16t² + 90t + 160
Divide both sides by -2:
0 = 8t² - 45t - 80
Quadratic equation:
t = [ -b ± √(b² - 4ac)] / (2a)
t = [ -(-45) ± √((-45)² - 4(8)(-80))] / (2(8))
t = [ 45 ± √(2025 + 2560)] / 16
t = [ 45 ± √(4585)] / 16
throwing out the negative time:
t = (45 + √4585) / 16
t ≈ 7.04 seconds