Question

Q2. If theta=45°, P.T Cos2theta = 2cos^2 theta - 1​

Answer 1

Answer:

KESE

Step-by-step explanation:

KESE

Answer 2

$\color{red}\huge{\underline{\underline{GIVEN\dag}}}$

• $\theta = 45$

$\color{red}\huge{\underline{\underline{SOLUTION\dag}}}$

$\cos2 \theta = 2 \cos^{2} \theta - 1$

$\implies \cos2(45) = 2 { \cos ^{2} (45) } - 1$

$\implies \cos(90) = 2( { \frac{1}{ \sqrt{2} } )}^{2} - 1$

$\implies \cos(90) = 2 (\frac{1}{2}) - 1$

$\implies \cos(90) = 2 - 1$

$\implies \cos(90) = 1$

$\therefore1 = 1$

$\therefore LHS=RHS$

HENCE,PROVED.

HOPE THAT HELPS!!