#1**+1 **

Since sin x can't be bigger than 1, assuming this is the question

cos (2x + 2) = sin x

*edit* That was a bad thing to assume!

This is probably not the answer you want.. see CPhill's answer vvvv

But if you did happen to mean that:

This is to make it easier to see that

x + (2x + 2) = 90

x + 2x + 2 = 90

3x = 88

x = 88/3

hectictar
Apr 13, 2017

#2**+2 **

cos 2x + 2 = sin x

1 - 2sin^2x + 2 = sinx

2sin^2x + sinx - 3 = 0

(2sin x + 3) ( sin x - 1) = 0

The first factor has no solution

For the second, we have

sin x - 1 = 0

sin x = 1 and this happens at pi/2 + 2pi*n where n is an integer

See the graph here showing the intersection points :

https://www.desmos.com/calculator/31maw6isd8

CPhill
Apr 13, 2017