a maths!!

1. prove the identity
( cos^2Θ-sinΘcosΘ+tanΘ)/(cos^2Θ+sinΘcosΘ-tanΘ)=(1+tan^3Θ)/1-tan^3Θ)
2.if cosΘ and cosecΘ are the roots of the equation 3x^2+hx-1=0 , where π/2<Θ<π , find the value of h and leave your ans in surd form
3.if sinΘ and ocsΘ are the two roots of the equation kx^2-4x+3=0 , find the possible value of k
4. if Θis an obtuse angle and the equation in x 3x^2-(4cosΘ)x+2sinΘ=0
has equal roots, find the value of Θ