Which graph represents the function y = cos(4x)?

Find f. A) 7.4 B) 8.2 C) 10.5 D) 11.1

tatyana61 [14]

F=72

g=6

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$\cos { \left( F \right) } =\frac { { e }^{ 2 }+{ g }^{ 2 }-{ f }^{ 2 } }{ 2eg }$

Therefore:

$\cos { \left( 72 \right) } =\frac { { e }^{ 2 }+{ 6 }^{ 2 }-{ f }^{ 2 } }{ 2\cdot e\cdot 6 } \\ \\ \cos { \left( 72 \right) } =\frac { { e }^{ 2 }+36-{ f }^{ 2 } }{ 12e }$

$\\ \\ 12e\cdot \cos { \left( 72 \right) } ={ e }^{ 2 }+36-{ f }^{ 2 }\\ \\ \therefore \quad { f }^{ 2 }={ e }^{ 2 }-12e\cdot \cos { \left( 72 \right) } +36\\ \\ \therefore \quad f=\sqrt { { e }^{ 2 }-12e\cdot \cos { \left( 72 \right) +36 } } \\ \\ \therefore \quad f=\sqrt { e\left( e-12\cos { \left( 72 \right) } \right) +36 }$

But what is e?

E=76

G=32

g=6

And:

$\frac { e }{ \sin { \left( E \right) } } =\frac { g }{ \sin { \left( G \right) } }$

Which means that:

$\frac { e }{ \sin { \left( 76 \right) } } =\frac { 6 }{ \sin { \left( 32 \right) } } \\ \\ \therefore \quad e=\frac { 6\cdot \sin { \left( 76 \right) } }{ \sin { \left( 32 \right) } }$

If you take this value into account, you will discover that f is...

$f=\sqrt { \frac { 6\cdot \sin { \left( 76 \right) } }{ \sin { \left( 32 \right) } } \left( \frac { 6\cdot \sin { \left( 76 \right) } }{ \sin { \left( 32 \right) } } -12\cos { \left( 72 \right) } \right) +36 } \\ \\ \therefore \quad f=10.8\quad \left( 1\quad d.p \right)$

So I would have to say that the answer is approximately (c).

6 0

2 years ago

PLEASE HELP I AM STRUGGLING

ArbitrLikvidat [17]

Answer:

y=-2x+2

Step-by-step explanation:

the slope intercept form is y=mx+b

slope - to find the slope from 2 point you do (y2-y1)/(x2-x1) so it would be

(14-2)/(-6-0). which out simplify to -2.

y-intercept - the y-intercept is given in one of the points (0,2).

5 0

2 years ago

Noelle and karina both leave the Internet cafe at the same time, but in opposite directions. If karina travels 9 mph faster than

Vesna [10]

Noelle goes east at N mph.
Karina travels west at N + 9
then their velocity between them is (N + N + 9)
After 8 hours they travel 8(2N + 9) = 232
(2N + 9) = 29
2N = 20
N = 10 mph for Noelle
N+9=19 mph for Karina

7 0

3 years ago

Electricity usage data consists of 45 months has a mean number of units consumed is 390.47 per month with a standard deviation o

neonofarm [45]

Answer:

The 95% confidence interval for the average monthly electricity consumed units is between 47.07 and 733.87

Step-by-step explanation:

We have the standard deviation for the sample. So we use the t-distribution to solve this question.

The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So

df = 45 - 1 = 44

95% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 44 degrees of freedom(y-axis) and a confidence level of $1 - \frac{1 - 0.95}{2} = 0.975$ . So we have T = 2.0141

The margin of error is:

M = T*s = 2.0141*170.5 = 343.4

In which s is the standard deviation of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 390.47 - 343.40 = 47.07 units per month

The upper end of the interval is the sample mean added to M. So it is 390.47 + 343.40 = 733.87 units per month

The 95% confidence interval for the average monthly electricity consumed units is between 47.07 and 733.87

6 0

2 years ago

Fazio chooses a jersey at random and then replaces it. He then selects a second jersey at random. What is the probability that f

Natalka [10]

Answer:

4% probability that fazio selects a striped jersey both times.

Step-by-step explanation:

A probability is the number of desired outcomes divided by the number of total outcomes.

In this problem:

For each jersey, there are 2+5+3 = 10 possible options, two of which are striped.

So twice 2/10

$p = (\frac{2}{10})^{2} = \frac{4}{100}$

4% probability that fazio selects a striped jersey both times.

5 0

2 years ago