Given:-

m^2 + m’^2 2mm’cosΘ = 1

n^2 + n’^2 + 2nn’cosΘ = 1

mn + m’n’ + (mn’ + m’n) cosΘ = 0

To Prove:-

m^2 + n^2 = cosec^2Θ

Please help! Can anyone do this sum??

:cool:

And one more important thing i want to say, is that I'm a class 10th student....

So please provide the easiest way round...