Question

evaluate cos^2 45+ cos^2 135+ cos^2 225+ cos^2 315​

Answer 1

Answer:

cos²45+cos²(90+45)+cos²(180+45)+ cos²(270+45)

=cos²45-sin²45-cos²45-sin²45

=(1/√2)²+(-1/√2)²+(-1/√2)²+(-1/√2)²

=1/2+1/2+1/2+1/2

=4/2

=2

Answer 2

Refer The Attachment ⬆️

$\red{\bf{MrMonarque}}$

Hope It Helps You ✌️