Question

plz solve this question....if u send me the pic of solution...then it will be very helpful for me...

Answer 1

ans is

we know angleA + angleB + angleC = 180 degree

A+B+C=180
B+C=180-A
DIVIDE BOTH BY 2

B+C÷2=180÷2-A÷2
B+C/2=90-A/2

now in question 1: cos^2A/2 +cos B+C/2

BUT VALUE OF B+C/2 IN QUESTION 1 , WE GET

COS^2 A/2+ COS^2 (90-A/2)
= COS^2 A/2 + SIN^2 A/2
( WE NOW COS 90-THETA IS SIN THETA)

so the ans wer will be 1 beacause cos^2 theta + sin^2 theta = 1

hence prove