F.4 A.Maths(help!!)

Can anyone help me to solve the following question?
The two roots of the equation 3x2-4x+k=0 are sin and cos, find the value of k
題目有問題，是不是
3x2-4x+k=0 的兩根為sinθ及cosθ
若是則
sinθ+cosθ = 4/3
及
sinθ cosθ = k/3
則
(sinθ+cosθ)2 = (4/3)2
sin2θ+2sinθcosθ + cos2θ = 16/9
因sin2θ + cos2θ = 1
則
2sinθcosθ = 16/9 = 7/9
2(k/3)= 7/9
k= 7/6

since there 2 roots, Discriminant >0
so (-4)^2 - 4(3)(k) > 0
solve the inequality