Question

Trigonometry

Answer 1

\(\bf tan(\theta) = \cfrac{b}{a} \implies \cfrac{sin(\theta)}{cos(\theta)}\\
sin(\theta) = b\qquad \qquad cos(\theta) = a\)

keeping that in mind, expand \(\bf acos(2\theta)+bsin(2\theta)\)

Answer 2

so cos2x=2sin^2x+1?? or 1-2cos^2x??