Question

1 et ( x^{n}=tan theta Rightarrow theta=tan ^{-1} x^{n} )
then, becomes',
( =frac{cos ^{-1} 1-tan ^{2} theta}{1+tan ^{2} theta} )
( =cos ^{-1} cos 2 theta )
( =20^{circ} cdot cos 20=frac{1-tan ^{2} theta}{1+tan ^{2} theta} )
( =2 tan ^{-1} x^{n}+because x^{n}=tan theta )
( =R cdot min )

# 2.1 8. cosilam tan- COS 2n

Solution