Question 183063
Find all solutions to the equation. Use a lower-case n to denote an arbitrary integer; separate your answers with commas; use the most compact expressions possible. 
-4cos(4x) + 2 = 0 
-4cos(4x) = -2
cos(4x) = 1/2
4x = 360n + 60, 360n + 300
x = 90n + 15º, 90n + 75º (in degrees)
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x = n*pi/2 + pi/12, n*pi/2 + 5pi/12 radians
x = pi(6n+1)/12, pi(6n+5)/12 radians