Question

Solve sin\theta +1 = cos2\theta

Answer 1

Step-by-step explanation:

sin ∅ + 1 = cos2∅

From multiple angles in trigonometry

cos2∅ = 1 - 2sin²∅

So we have

sin∅ + 1 = 1 - 2sin²∅

sin∅ +1 - 1 + 2sin²∅= 0

sin∅ + 2sin²∅ = 0

Factor out sin∅

sin∅ ( 1 + 2sin∅) = 0

sin ∅ = 0

∅ = 0° , 180°

1 + 2sin∅ = 0

2sin∅ = - 1

sin ∅ = -1/2

∅ = 210° , 330°

The solutions are

0° , 180° , 210° , 330°

Hope this helps you