Calculus problem

Question

Which one of the following statements is true?

Options:

1. If f and g are differentiable, then  .
2. 
3. If f and g are differentiable, then  .
4. None of these statements are true

Answer 1

option #3

y = sqrt( f(x))

then

y' = f'(x) / [ 2 sqrt(f(x))] by power and chain rules

option #1 is an INCORRECT statement of the product rule.

option #2 is incorrect because |x^2+x| = sqrt( (x^2+x) ^2 |

and the derivative is incorrect