Question

find the value of sin^2 20°+sin^2 70°-tan^2 45°

Answer 1

Given, sin^2 20°+sin^2 70°-tan^2 45°

= sin^2 20°+sin^2(90° - 20°) - tan^2 45°

= sin^2 20°+cos^2 20°-1

= 1 - 1

= 0 (Ans.)