To derive the equation, we first use the identity that
\sin{2\theta}=2\sin{\theta}\cos{\theta}$$.
So the integration content now is $$\sin{2\theta}/2$$.
The integral result is $$-\frac{1}{4}\cos(2\theta)$$,
$$=0.25*(1-2\sin{x}^2)$$ and the result is identical to the slide.
To derive the equation, we first use the identity that
\sin{2\theta}=2\sin{\theta}\cos{\theta}$$. So the integration content now is $$\sin{2\theta}/2$$. The integral result is $$-\frac{1}{4}\cos(2\theta)$$, $$=0.25*(1-2\sin{x}^2)$$ and the result is identical to the slide.