Question

If sin(2x + 7)degrees =cos(4x-7)degrees, what is the value of x?

Answer 1

x = 15

Explanation:

`cosx = sin((\pi)/(2) - x)`

`sin x = sin y = > x = sin^(-1)(sin y) = y => x = y`

`sin(2x + 7)^(\circ) = cos(4x - 7)^(\circ)\\\\sin(2x + 7)^(\circ) = sin((\pi)/(2) - (4x - 7))\\\\(2x + 7) = ((\pi)/(2)- (4x -7))\\\\2x + 7 = (\pi)/(2) - 4x + 7\\\\6x = (\pi)/(2)\\\\x = (\pi)/(12)`

x = 15