1) If Tan A=5/6 and Tan B =1/11.Prove A+B= Pi/4

2.)Find general sol. of 7cos²Ɵ +3Sin² Ɵ =4

3.) Find gen.sol of 2sin²x +sin²x=2

tan(a+b)=tana+tanb/1-tanatanb

tan(5/6+1/11)=tan 5/6+tan 1/11/ 1-tan 5/6 tan 1/11

tan(61/66)=the ame thing

then u can prove it

2..7(1-sin2)+3sin2'=4

7-7sin2+3sin2=4

-4sin2=-3

sin2=3/4

sin=root3/2

then write it as =npie+(-1)nalpha

3.sin2(3)=2

sin2=2/3

sin=root2/root3

thenwrite it in the same form

hope this helps u