Question

Getting nowhere...

Calculate f'(pi / 3) when f(x) = 2 sin x

Answer 1

could you differentiate 2sin x ?
hint derivative of sin x = cos x

Answer 2

hmm, I thought you had to convert f'(pi / 3) to a primitive function?

Answer 3

If I derivate "the right side" I get:

Answer 4

i don't know what a primitive function is...
f'(x) means derivative of f(x)
f'(pi/3) means derivative of f(x) at x = pi/3

Answer 5

If I derivate "the right side" I get:

pi / 3 = 2 cos x

...is that solvable?

Answer 6

oh and I have to do it without a calculator, so it *should* be something simple :P

Answer 7

well, nothing, I have no idea how to do that calculation without a calculator, which is why I think it's wrong. I think pi / 3 should be converted to a primitive function and *that* value set to 2 sin x

Answer 8

no, f'(pi/3) means derivative of f(x) at x = pi/3
so, put x=pi/3 in f'(x)
f'(pi/3) = 2 cos (pi/3)=...?

Answer 9

cos (pi/3) can be found without calculator, as pi/3 is standard angle

Answer 10

hmm, you're right!

Answer 11

i know! :')