Question

Sabendo que A= $\frac{\sqrt 2}{2} + cos3x + cos \frac{x}{2}$ e que $x= \frac{/pi}{2}$, determine o valor de A.

Answer 1

cos 3x = cos 3π/2 = cos 270°= 0

cos x/2 = cos π/4 = cos 45° = √2/2

Logo:

A = √2/2 + 0 + √2/2

A = (2√2)/2

A = √2