Question

Evaluate cos square 30 degree +sin square 45 degree-1/3 tan square 60 degree+cos 9p degre

Answer 1

cos^2 30 + sin^2 45 - 1/3 tan^2 60+ cos 90

= ( root3/ 2 )^2 + (1/2)^2 - 1/3 (root 3)^2 +1

= 3/4 + 1/4 -1/3 × 9 + 1

= 1 - 3 + 1

= -1