Question

√2 cos (π\4-A)= cos A +sin A​

Answer 1

Step-by-step explanation:

√2 cos (π\4-A) =

√2 (cos π/4 cos A + sin π/4 sin A)

[ since, cos(A+B) = cos A cos B + sin A sin B]

= √2 (1/√2 * cos A + 1/√2 * sin B)

taking 1/√2 as common,

= √2*1/√2 (cos A + cos B)

= cos A + cos B