Derivative of y=(sint)²

1. Let $u = \sin{\left(t \right)}$.

2. Apply the power rule: $u^{2}$ goes to $2 u$

3. Then, apply the chain rule. Multiply by $\frac{d}{d t} \sin{\left(t \right)}$:

   1. The derivative of sine is cosine:

      $$\frac{d}{d t} \sin{\left(t \right)} = \cos{\left(t \right)}$$

   The result of the chain rule is:

   $$2 \sin{\left(t \right)} \cos{\left(t \right)}$$

4. Now simplify:

   $$\sin{\left(2 t \right)}$$

The answer is:

$$\sin{\left(2 t \right)}$$