Page 3 - CH-7-SLRC-HOME ASSIGNMENT
P. 3
23. 2 dx 1 log x a c .
x a 2 2a x a
24. 2 dx 1 log a x c
a x 2 2a a x
25. dx log x x a
2
2
c
2
x a 2
2
26. dx log x x a
2
c
x a 2
2
27. Forms of partial fractions:
px q A B
(i) ,a b;
(x a)(x b) x a x b
px q A B
(ii) ;
(x a) 2 x a (x a) 2
px 2 qx r A B C
(iii) ;
(x a)(x b)(x c) x a x b x c
px 2 qx r A B C
(iv) ;
2
(x a) (x b) x a (x a) 2 x b
px 2 qx r A B C D
(v) ;
3
(x a) (x b) x a (x a) 2 (x a) 3 x b
px qx r A Bx C
2
(vi) ; , where x 2 bx c cannot be factorised.
(x a)(x bx c) x a x bx c
2
2
28. Integration by parts
f(x)g(x)dx f(x) g(x)dx [f'(x) g(x)dx]dx = first function × integral of second function –
integral of {product of differential of first and integral of second}.
29. e [f(x) f'(x)]dx e f(x) c.
x
x
x x a 2 a 2
2
2
30. x a dx log x x a .
2
2
2
c
2 2
2
2
2
2
31. x a dx x x a 2 a 2 2 log x x a
2
c
2
2
2
2
32. a x dx x a x 2 a 2 sin 1 x c .
2 2 a
33. Integrals of the form dx . We can express the integrand as dx . Now we
2
ax 2 bx c a[(x 2 ]
)
can use formula (13) given above for 2 dx .
x a 2