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3 years ago

Find an identity for cos(4t)

1 answer:

5 0

We must know that $\cos(2x)=2\cos^2(x)-1$ . So:

$\cos(4t)=\cos(2\cdot2t)\\\\
\cos(4t)=2\cos^2(2t)-1\\\\
\cos(4t)=2(2\cos^2(t)-1)^2-1\\\\
\cos(4t)=2(4\cos^4(t)-4\cos^2(t)+1)-1\\\\
\cos(4t)=8\cos^4(t)-8\cos^2(t)+2-1\\\\
\boxed{\cos(4t)=8\cos^4(t)-8\cos^2(t)+1}$

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Kim's softball team was playing in the championship game. When there were 444 innings left, the team was losing by a score of 17

olga nikolaevna [1]

The inequality to determine the number of runs per inning, p Kim's team could have scored is; 4r + 6 > 17

<h3>How to write an Inequality?</h3>

Let r represent the number of runs per inning. Thus for 4 innings, we have 4r.

The team already has 6 runs. Now add the additional runs to this to get;

4r + 6

The team wants to score more than the other team, this means they need more than 17 and so the inequality required is;

4r + 6 > 17

Subtract 6 from each side to get;

4r + 6 - 6 > 17 - 6

4r > 11

Divide both sides by 4 to get:

r > 2.75

Approximating to a whole number gives;

r > 3

Read more about writing inequalities at; brainly.com/question/25275758

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8 0

1 year ago

Graph y=2/5x, use x as -2,-1,0,1,2

Natali [406]

Plot a graph of y-axis against x-axis.

The graph should be a straight line passing through:

(-2,0.8) , (-1,-0.4) , (0,0) , (1,0.4) and (2,0.8)

4 0

2 years ago

Sara bought a used car for $10,000. She learned from online that the value of a car depreciated 15% per year. What is the formul

Fudgin [204]

Answer:

Step-by-step explanation:

Value of Sam's car after t years =

= $=10000*(1-\frac{15}{100})^{t}\\\\=10000*(\frac{85}{100})^{t}\\\\=10000*(0.85)^{t}$

Value of Sam's car in 5 years=

$=10000*(0.85)^{5}\\\\=10000*0.4437\\\\$

= $ 4437

4 0

3 years ago

Plsss helppp!!!!!!!!!!!!!!

azamat

Answer:

yes

Step-by-step explanation:

A statistical question is one that can be answered by collecting data and where there will be variability in that data.

because not every father would be born on the same day this is a statistical question.

8 0

3 years ago

Find the inverse of the following function

KatRina [158]

f-¹(x)= $\frac{2-7x}{x+2}$

Answer:

Solution given:

f(x)= $\frac{-2x+2}{x+7}$

Let f(x)=y

y= $\frac{-2x+2}{x+7}$

Interchanging role of x and y

x= $\frac{-2y+2}{y+7}$

doing crisscrossed multiplication

x(y+7)=-2y+2

now solve it:

xy+7x=-2y+2

keep like terms in one side

xy+2y=2-7x

take common

y(x+2)=2-7x

make a value of y

y= $\frac{2-7x}{x+2}$

So,

f-¹(x)= $\frac{2-7x}{x+2}$

3 0

2 years ago

Read 2 more answers