how about , let cos(theta) = x
then your equation becomes
6x^2 - 5x + 1 = 0
which factors to
(2x - 1)(3x - 1) = 0
x = 1/2 or x = 1/3
then
cos(theta) = 1/2 or cos(theta) = 1/3
theta = 60º or 300º or theta = 70.5º or 289.5º
I got this far, but now I'm stuck...please help
6cos^2theta - 5cos(theta) + 1 = 0
6cos^2theta - 5cos(theta) = -1
cos(theta) * {6cos(theta) - 5} = -1
1 answer
1 answer