Question

Solve ${\cos }^2{x}^3$

Answer 1

Consider the given expression,

$\Rightarrow {\cos }^2{x}^3$

$\because \cos 2A=2{\cos }^{2}A-1$

Put,$A=x^3$

$\therefore \cos 2x^3=2{\cos }^2{x}^3-1$

$\therefore {\cos }^2{x}^3=\frac{\cos 2x^3+1}{2}$

Hence, this is the answer.