Question

$2sin^{2} x+sinx-1=0$

Answer 1

Answer:

Hey mate, here is your solution.

$2 {sin}^{2} x + sinx - 1 = 0 \\ 2 {sin}^{2} x + 2sinx - sinx - 1 = 0 \\ 2sinx(sinx + 1) - 1(sinx + 1) = 0 \\ (2sinx - 1)(sinx + 1) = 0$

Therefore,

$sinx = \frac{1}{2} \: or \: - 1$

Follow me ❤

Answer 2

Answer:

2sin^2x+sinx-1=0

2sin^2x+2sinx-sinx-1=0

2sinx(sinx+1)-1(sinx+1)=0

(sinx+1)(2sinx-1)=0

therefore sinx=-1 and 1/2

if sinx=-1 then x= 3pi/2+2pi n (for any integer n)

and if sinx=1/2 then x=30°