Question

If sin (2 x + 5)° = cos (5 x +20)°, find the value of x.

Answer 1

Answer:

x=9.29

Step-by-step explanation:

$\boxed{Formula \:used:\: cos\theta = sin(90\degree-\theta)}\\\sin (2 x + 5)\degree = \cos (5 x +20)\degree\\\sin (2 x + 5)\degree = \sin\{90- (5 x +20)\}\degree\\ (2 x + 5)\degree = \{90- (5 x +20)\}\degree\\\\ (2 x + 5) = 90- (5 x +20)\\ (2 x + 5) + (5 x +20) = 90\\7x+25=90\\7x= 90-25\\7x=65\\x=\frac{65}{7} \\x=9.285714285\\x=9.29$