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I really need help with this question. Please help me. Thanks!
If f(x)=6cosx-1, algebraically determine algebraically the x intercepts to the nearest tenth. On the domain x E R.

whenever cos x = +1/6

in quadrant 1, when x = 80.4 degrees
then in quadrant 4 when x = 279.6 degrees
then every 360 degrees after each of those.