Question

prove that sin2¢+cos¢=0​

Answer 1

★Heya★

Sin (2ß) = 2 Sin (ß) × Cos (ß)

=>

Sin 2c + Cos c = 0

=>

2 Sin c × Cos c + Cos c = 0

=>

Cos c { 2 Sin c + 1 } = 0

=>

Cos c = 0

OR

{ 2 Sin c + 1 } = 0

=>

Cos c = Cos 90

c = 90

OR

Sin c = -1/2

Sin c = Sin 120

c = 120

So,

c = 90

OR

c = 120

Answer 2

cosa-sina=root over 2 sina

cosa=(root over 2 +1) sina

sina =1÷(root over 2+1)cosa

rationalize the denominator to get:

sin(a) =(root over 2 -1) cos (a)

bring cos to other side to get:

sin(a)+cos(a)=root over 2 cos (a)

i hope u have got the answer....