Question

Consider the function
http://prntscr.com/90izfw

Answer 1

Take the derivative for the function:

f'(x) = 2 + 3cos(x)

let , f'(x) = 0

3cos(x) = -2

cos(x) = -2/3 (negative in 2nd, 3rd quarter) ( in the interval (0, 360) )

x = 180 - 48.18 = 131.8 , x = 180 + 48.18 = 228.18