Question

can someone help me step by step with...

the derivative of
y=7cos^4(x)

Answer 1

You can rewrite the equation as follows:
\[y=7(\cos x)^{4}\]
Then use the chain rule to find the derivative.

Answer 2

It might help to look at the problem in this format.
\[y=7(cosx)^{4}\]

Answer 3

@monroe17 Can you use the chain rule?

Answer 4

28cos(x)*-sin(x)

Answer 5

wait hold on i messed up

Answer 6

what'd i do wrong?...

Answer 7

nvm got it

Answer 8

28cos^3(x)*-sin(x)

Answer 9

nope its wrong ;/ what'd i do lol?

Answer 10

\[\frac{dy}{dx}=\frac{d.7(\cos x)^{4}}{d.\cos x}\times \frac{d(\cos x)}{dx}\]

Answer 11

@monroe17 Your last posting is correct.

Answer 12

is 28cos^3(x)-sin(x) the same as -28cos^3(x)sin(x)?

Answer 13

28cos^3(x)*-sin(x)

Answer 14

it is. you just forgot to multiply 28 and -1.

Answer 15

oh okay thanks!

Answer 16

\[28(\cos x)^3(-sin x)\] should be clearer.