`1)sin^2 x+3sin x-cos^2 x=-2`
`<=>sin^2 x+3sin x-1+sin^2 x+2=0`
`<=>2sin^2 x+3sin x+1=0`
`<=>[(sin x=-1),(sin x=-1/2):}`
`<=>[(x=-\pi/2 +k2\pi),(x=-\pi/6 +k2\pi),(x=[7\pi]/6+k2\pi):}` `(k in ZZ)`
`2)sin^2 x+sin x-cos^2 x=0`
`<=>sin^2 x+sin x-1+sin^2 x=0`
`<=>2sin^2 x+sin x-1=0`
`<=>[(sin x=-1),(sin x=1/2):}`
`<=>[(x=-\pi/2 +k2\pi),(x=\pi/6 +k2\pi),(x=[5\pi]/6 +k2\pi):}` `(k in ZZ)`