Did I answer this correctly? Math

1. If f(x) = sin(x) then f'(x) = ?
answer: cosx

2. If f(x) = cos(x) then f'(x) =?
answer: -sin(x)

3. If f'(x) = sin(x) then f(x) =?
answer: -cos(x)

all answers are correct

You are correct.