Question

2sin^2x+sinx-1=0

Answer 1

let u = sin(x)

2u^2 + u - 1 = 0

Answer 2

Can you solve this?

Answer 3

could you expand to the next step?

Answer 4

can't you just solve as a quadratic ... or cant you roll this way because its trig?

Answer 5

next step:
factorise:
(2u-1)(u+1)=0
thus
2u-1 = 0 or u+1=0
u=1/2 u=-1

now sub back sinx

Answer 6

is your domain for x specified?

Answer 7

sinx = 1/2 or sinx=-1 now solve for x

Answer 8

ahh, got it! I didn't realize it was a quadratic. Thank you so much!