Question

If 4 cos² x° -1=0 and 0 _<x°_<90°.find : i) x° ii) sin²x°+cos²x° iii) 1/cos²x°-tan²x°

Answer 1

cos x = 1/2

x = 60.

(i) x = 60

(ii) sin2x+cos2x = 1

(iii) 4-1/3 = 11/3