(\cos^2 , 1^\circ + cos^2 2^0 + cos^2 , 3^0 + ... + \cos^2 ,... | Mathematics | SolveeIt | Solveeit

Today, August 20

Question

$\cos^2 \, 1^\circ + cos^2 2^0 + cos^2 \, 3^0 + ... + \cos^2 \, 90^\circ$ =

A

0

B

1

C

45

D

$\frac{89}{2}$

Answer

$\frac{89}{2}$

Explanation

Solution

If $(A + B) = 90^\circ$ then $(\cos^2 \, A+ \cos^2 \, B) = 1$