Question

Solve 3sin2x-cosx, for 0°<=x<=180°

Answer 1

Answer:

Answer:

0

,

48

∘

19

,

180

∘

,

311

∘

81

,

360

∘

Explanation:

Since sin 2x = 2sin x.cos x, we get:

4sin x - 6sin x.cos x = 0

sin x(4 - 6cos x) = 0

Trig table and unit circle -->

a. sin x = 0 -->  

x

=

0

,  

x

=

180

∘

, and  

x

=

360

∘

b. 4 - 6cos x = 0

cos x = 4/6 = 2/3 --> x = +- 48^@19

Arc (-48.19) and arc (360 - 48.19 = 311.81) are co-terminal

Answers for (0, 360)

0

,

48

∘

19

,

180

∘

,

311

∘

81

,

360

∘