We know that ( 1 ) ∫ f ′ ( x ) f ( x ) d x = ln | f ( x ) | + c
( 2 ) ∫ 1 U 2 + 1 d x = tan − 1 U + c
Now I = ∫ 2 x − 5 x 2 + 2 x + 2 d x
= ∫ 2 x + 2 − 7 x 2 + 2 x + 2 d x
= ∫ 2 x + 2 x 2 + 2 x + 2 d x − ∫ 7 x 2 + 2 x + 2 d x
= ∫ d d x ( x 2 + 2 x + 2 ) x 2 + 2 x + 2 d x − 7 ∫ 1 x 2 + 2 x + 1 + 1 d x I = ∫ d d x ( x 2 + 2 x + 2 ) x 2 + 2 x + 2 d x − 7 ∫ 1 ( x + 1 ) 2 + 1 d x Using ( 1 ) and ( 2 ) , we get I = ln ∣ ∣ x 2 + 2 x + 2 ∣ ∣ − 7 tan − 1 ( x + 1 ) + c