= 2 − 2 tan( ) = 2 [1 − tan( )]
=
1 − tan( )
The integral is
/3
1 − tan( )
∫
2
2
cos ( ) + 1
0
/3
1 − tan( )
∫ .
+ 1 2 [1 − tan( )]
0
1 /3
= ∫
2 0 ( + 1)
To perform this integration, need to express it as
partial fractions,
1
= +
( + 1) + 1
1 = ( + 1) +
Or
1 = + +
3