Question

If cosx =sin20, find the value of x, 0

Solve for x correct to the nearest minute given sin^2 x-3sin xcosx+2cos^2 x=0, where 0≤x≤180

Answer 1

First find the sine of 20 degrees = 0.34202
Now if we look up the arc cosine of 0.34202 it will be the angle x we are looking for.
arc cosine of 0.34202 = 70 degrees