Question

proof the identity sin55+cos81=cos21​

Answer 1

sin 51 + cos 81 = cos 21

L.H.S. = sin 51 + cos 81

= sin 51 + sin 9

[coz cos(90 - x) = sin x]

= 2 sin 30 cos 21

{coz sin A + sin B = 2 sin [(A+B)/2] cos [(A-B)/2]}

= cos 21 = R.H.S.

Answer 2

Answer:

Nhi aata

Step-by-step explanation:

Meri bhen ko bhi nhi aata