Question

(cos²20° + cos²70°/sin²20°+sin²70°)+sin²64°+cos64°sin26°

Answer 1

Answer:

Step-by-step explanation:

(cos²20° + cos²70°/sin²20°+sin²70°)+sin²64°+cos64°sin26°

We know that,

Cos20° = Cos(90° -70°) = Sin70°   (∵ Cos (90-θ) = Sinθ)

Sin20° = Sin ( 90° - 70°) = Cos70°  (∵ Sin (90-θ) = Cosθ)

Sin26°  = Sin (90° - 64°) = Cos64°  (∵ Sin (90-θ) = Cosθ)

Substitute the values in above equation.

(cos²20° + cos²70°/sin²20°+sin²70°)+sin²64°+cos64°sin26°

= (Sin²70° + Cos²70°/Cos²70°+Sin²70°) + Sin²64° + Cos64° * Cos64°

= (1 / 1) + Sin²64° + Cos²64°  (∵ Sin²θ + Cos²θ = 1)

= 1 + 1

= 2