Compute the derivative of `f(x)=sin^2x`.

Explanation

To compute the derivative of the function \( f(x) = \sin^2 x \), we can use the first principle of derivatives, also known as the limit definition of the derivative.

### Step-by-Step Solution:

1. **Write the definition of the derivative**:
The derivative of a function \( f(x) \) is given by:
\[
f'(x) = \lim_{h \to 0} \frac{f(x+h) - f(x)}{h}
...