Question

solve 2sin^2x - sinx -1 greater than zero​

Answer 1

Step-by-step explanation:

2sin^2x -sinx -1 >0

2sin^2x -(2-1) sinx -1>0

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

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

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

if 2sinx +1 >0

2 sinx > -1

1

sinx > - -----

2

sinx> sin (4π/3)

x > 4π/3

if sinx -1>0

sinx > 1

sinx > sin(π/2)

x > π/2

x > 4π/3 and x >π/2

so x>4π/3

Answer 2

Answer:

Step-by-step explanation:

sinx > 1

sinx > sin(π/2)

x > π/2

x > 4π/3 and x >π/2

so x>4π/3