Prove that :

Question 1 :
[tex]sec^2 \theta +cosec^2\theta = (tan \theta +cot \theta )^2[/tex]

Question 2 :
[tex]\frac{1-tan^2\theta}{1+tan^2\theta} =(cos +sin \theta)(cos \theta -sin \theta)[/tex]

Question 3 :
[tex]\frac{sin \theta}{1-cot \theta}+\frac{cos \theta}{1-tan \theta} =cos \theta +sin \theta[/tex]