Question

If 2 cos square theta + sin theta -2 =0 find the value of theta
And the answer is 0°or 30°
Plz answer plz plz

Answer 1

$2 \cos ^{2} (x) + \sin(x) - 2 = 0 \\ 2(1 - \sin^{2} (x) ) + \sin(x) - 2 = 0 \\ 2 - 2 \sin ^{2} (x) + \sin(x) - 2 = 0 \\ 2\sin ^{2} (x) - \sin(x) = 0 \\ \sin(x) (2 \sin(x) - 1) = 0 \\ \sin(x) = 0 \\ x = 0° \: \: \: (1) \\ \\ 2 \sin(x) - 1 = 0 \\ \sin(x) = \frac{1}{2} \\ x = 30° \: \: \: (2)$

From (1) and (2), We can conclude the answer to be 0° and 30°.

Answer 2

Answer:Here is your answer

Step-by-step explanation:

2(1-sin² theta )+sin theta -2=0

2- 2sin² theta+sin theta -2=0

2 sin² theta - sintheta=0

sin theta(2sin theta -1)=0

2sin theta -1=0

sin theta=1/2

sin theta=30°