Question

The value of `cos^2  π/16 + cos^2  (3π)/16 + cos^2  (5π)/16 + cos^2  (7π)/16` is ______.

विकल्प

• 2

• 1

• 0

• None of these

Answer 1

The value of `cos^2  π/16 + cos^2  (3π)/16 + cos^2  (5π)/16 + cos^2  (7π)/16` is 2.

Explanation:

`cos^2  π/16 + cos^2  (3π)/16 + cos^2  (5π)/16 + cos^2  (7π)/16`

`cos^2  π/16 + cos^2  (3π)/16 + cos^2(π/2 - (3π)/16) + cos^2(π/2 - π/16)`

= `cos^2  π/16 + cos^2  (3π)/16 + sin^2  (3π)/16 + sin^2  π/16`

= 1 + 1

= 2