ULTIMATE FORMULA HANDBOOK
MATHONGO
Basic Formulas
cosec 2 xdx cot x
dx x
x
n
sec x tan xdx sec x
n 1
x dx n 1 ( n 1)
x
cosec x cot xdx cosec x
dx sec 1 x
2
x 1
a x dx
ax
,a 0
log e a
e x dx e x
1
dx log | x |
x
cos dx sin x
1
1 x
2
sec 2 xdx tan x
1
1 x
2
tan x d x log
sec x c
cot x dx lo g
sin x c
dx sin 1 x
sin xdx cos x
sec x dx log
1
dx tan 1 x
x
sec x tan x c log tan c
2
4
cos ec x dx log
cos ec x cot x c tan x 2 c
Method of Substitution
Type 1
Type 3
Type 4
f ´( x)
dx log f ( x) c
f ( x)
Type 2
n
f ( x )
f ´( x ) dx
f ( x ) n 1
c
n 1
f g ( x ) g ´( x ) dx . In this type, we substituteg (x) = t, then, Hence integral reduces to f (t) dt
P( x).(ax b) n
or
Working Rule :
P ( x)
(ax b)n
where P(x) is a polynomial in x and n is a positive rational number.
Put z = ax + b
Type 5
sin f(x) or cos f(x) then put z = f(x)
Type 6 :
s in m x c o s n x d x
Working Rule :
(i)
If power of sin x is odd positive integer, put z = cos x
(ii)
If power of cos x is odd positive integer, put z = sin x
(iii) If powers of both sin x and cos x are odd positive integers, put z = sin x or z = cos x.
(iv)
If powers of neither cos x nor sin x is odd positive integer, see the sum of powers of sin x and cos
x.
(a)
If the sum of powers is even negative integer, put z = tan x.
(b)
If the sum of powers (m + n) is even positive integer and m, n are integers, express the
integrand as the algebraic sum of sines and cosines of multiple angles.
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ULTIMATE FORMULA HANDBOOK
m
x sec n xdx or
m
x sec n xdx : similar can be derived for the other pair
Type 7 :
tan
.
tan
For
MATHONGO
cot
m
xco sec n xdx
(i)
If power of secx is even positive integer, put z = tanx.
(ii)
If power of secx is not even positive integer, then see the power of tanx.
(a)
If power of tanx is odd positive integer, put z = secx.
(b)
If power of tanx is even positive integer, then put sec2x – 1 in place of tan2x and then
substitute z = tanx.
(iii) If power of tanx is zero and power of secx is odd positive integer greater than 1, then method of
integration by parts is used.
SOME
STANDARD SUBSTITUTIONS
1
1.
2.
a
2
x
2
or
1
a2 x2
2
a x
1
or
2
a2 x2
x = a sin or a cos
x = a tan or a cot
6.
x
a x or
7.
x a
or
b x
4.
2
or
x2 a 2
a x
a x or
x a
2
x = a sec or a cosec
x a
x b
8.
a x
a x x = a cos 2
x
a b x
x = a cos2 + b sin2
1
3.
1 x
x = a tan2 or x = a cot2
x
or
x
a x b
x = a sec2 – b tan2
5.
x
a x or
a x
x = a sin2 or x = a cos2
x
1
9.
a x b
x
x – a = t2 or x – b = t2
SOME STANDARD FORMULAS DERIVED FROM SUBSTITUTION
Set-I
Set-II
1.
x2
3.
x2
1.
3.
dx
a
dx
a
2
dx
2
a x
2
dx
2
1
x a
log
c
2a
x a
2
x a
2
2.
a2
2.
4.
dx
x
2
1
a x
log
c
2a
a x
1
x
c
tan 1
a
a
sin 1
x
c
a
log x
x2 a 2 c
dx
2
x a
2
dx
x x2 a2
INDEFINITE INTEGRATION
log x
x2 a 2 c
1
x
sec 1
c
a
a
ULTIMATE FORMULA HANDBOOK
Set-III 1.
2.
3.
MATHONGO
a2
x
sin 1 c
2
2
a 2 x 2 dx
x
2
a2 x2
x 2 a 2 dx
x
2
x2 a2
x 2 a 2 dx
x
2
x 2 a 2 dx
a2
lo g x
2
x
2
x2 a2 c
x2 a2
a2
lo g x
2
x2 a2 c
INTEGRATION BY PARTS
Integral of product of two functions
= (1st function) × (Integral of 2nd function) – Integral of {(differential of 1st function) × Integral of 2nd function}
d
f ( x). g( x) dx dx
In symbols : f ( x). g ( x) dx f ( x). g ( x) dx
dx
or
u.vdx u vdx – u´( vdx)dx
where
I stands for Inverse circular function
L stands for Logarthmic function
A stands for Algebraic function
T stands for Trigonometrical functions
and E stands for Exponential function
(ii)
If both the functions are trigonometrical, take that function as v whose integral is simpler.
(iii) If both the functions are algerbraic take that functions as u whose d c is simpler.
Standard Forms derived using By Parts
x
f ( x ) f ´ x dx e x f ( x ) c
(i)
e
(iii)
[ xf ´( x) f ( x)]dx x f ( x ) c
(iv)
(v)
e
e
ax
ax
sin bx c dx = eax
cos bx c dx = eax
(ii)
mx
e
mf (x) f ´ x dx emx f (x) c
b
sin bx c tan1
a
c
a2 b2
b
cos bx c tan1
a
c
a2 b2
INDEFINITE INTEGRATION
ULTIMATE FORMULA HANDBOOK
MATHONGO
METHOD : INTEGRATION BY PARTIAL FRACTION
We have divided this method into 2 types, depending upon the denominator.
1.
If denominator has non repeated factors
2.
If denominator has repeating factors
Type 1 : For non-Repeating roots
When denominator can be expressed as non repeating factors
i.e. D(x) = (x – 1) (x – 2)...
(for linear factors)
2
= (ax + bx + c) (px + qx + r)... (for quadratic factors)
Type 2
When repeating factors are present i.e. when denominator is of the form
k1
D(x) = (x – )
(x – )k2 ... {for linear factor}
= (ax2 + bx + c)k1 (px2 + qx + c)k {for quadratic
(1)
If function is linear.
N( x)
i.e.
(2)
2
( x a) ( x b) ( x c)
B1
C3
A
B2
C1
C2
= ( x a) ( x b)
2
2
( x c) ( x c)
( x b)
( x c)3
3
If function has quadratic factors
N( x)
i.e of the form
2
(ax bx c) ( px2 qx c)2
=
Ax B
2
ax bx c
P1 x Q1
px
2
qx r
P2 x Q2
px
2
qx r 2
INTEGRATION OF RATIONAL & IRRATIONAL FUNCTIONS
Integral of the form
ax
dx
2
bx c
,
dx
2
and
ax bx c
ax 2 bx c dx
For evaluating such integral we make the coefficients of x2 in ax2 + bx + c as one. Complete the square
by adding and subtracting the square of half of the coefficient of x to get the form
2
c
b2
b
a x
a 4 a2
2a
Integrals of the form ax
px q
2
bx c
dx,
px q
ax 2 bx c
dx
and ( px q) ax 2 bx c dx
For evaluating such integrals we choose suitable constants A and B such that
d
px q A
( ax 2 bx c) B
dx
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ULTIMATE FORMULA HANDBOOK
px 2 qx r
Integrals of the Form :
MATHONGO
ax 2 bx c
dx
For evaluating such integrals we choose suitable constants, A, B and C such that
d
(ax2 bx c C
px2 + qx + r = A (ax2 + bx + c) + B
dx
Integrals of the form :
x
x2 1
4
kx 2 1
dx
For evaluating such integrals, divide the numerator and denominator by x2. Complete the square of
2
2
1
1
denominator to get the form x a or x a
x
x
Then the integral can be evaluated by using the method of substitution.
Special Integration
Type I
Type II
Type III
x
x
x
x2 q
4
Divide numerator & denominator by x2
px2 q
dx
4
px2 q
x2 r
4
write this in form
px2 q
dx
1
2
q
x
2
q x2
4
dx
a b cos x
or
dx
x px q
express x2 + r as
2
x2 + r = l x q + m
where l + m = 1
&
a b sin x
or
q l m r
dx
a b cos x c sin x
2 tan
Working Rule :
2
Integration of Trigonometric Functions
Type I
q
Put sin x
x
2
x
2
cos x
2 x
1 tan
2
1 tan 2
1 tan 2
x
2
whichever is needed and then put z = tan
x
2
and
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x
2
q
ULTIMATE FORMULA HANDBOOK
Type II
MATHONGO
sin x
dx,
a sin x b co s x
cos x
d x , or
a sin x b co s x
p sin x q co s x
dx
c s in x b co s x
Step – 1 : Put Numerator = A (dinominator) + B (derivative of denominator.) where a 0, b 0
Step – 2 : Then equate the coefficients of sinx and cosx to find A and B.
a sin x b cos x c
p sin x q cos x r
Type 3.
(i)
Write Numerator = (Diff. of denominator) + µ (Denominator) + v
i.e. a sin x + b cos x + c = (p cosx – q sinx) + µ (psin x + q cosx + r) + v
Type 4.
a sin
1
2
2
x b cos x
dx .
1
a b sin
2
x
dx ,
1
a b cos
2
x
dx,
1
a sin x b cos x
(i)
Divide numerator and denominator both by cos2x
(ii)
Replace sec2 x, if any, in denominator by 1 + tan2 x
2
dx,
a b sin
1
2
x cos2 x
dx
(iii) Put tan x = t so that sec2 x dx = dt
This substitution reduces the integral in the form
Integrals of the form :
at
1
2
bt c
dt
dx
P
Q
where P and Q are linear or quadratic expression in x
1.
Q is linear and P is linear or quadratic., For evaluating such integrals, put Q = t2
2.
Q is quadratic and P is linear., For evaluating such integrals, put P =
3.
Both P and Q are pure quadratic., For evaluating such integrals, put x
1
t
1
.
t
Integration of Irrational Functions
Types of functions (intergrand)
Approach
1.
ax b a / n
f x,
a, b, c, d, , n R
cx d
Substitute :
2.
f x, ax b
a/n
, ax b
/m
ax b
tn
cx d
ax + b = tp, where p is L.C.M. of m and n.
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ULTIMATE FORMULA HANDBOOK
3.
f x
a 2 x2
MATHONGO
n
Workrule : x
m + p N, m + p > 1
Workrule : a + bx = tx
a2 x2 t
1
4.
x m a bx
p
1
5.
6.
m
L1 x
n
L 2 x
(i)
If n > m;
L1 ( x)
t
L 2 ( x)
(ii)
If n < m;
L 2 ( x)
t
L1 ( x)
(i)
If p I, substitute x = ts
where s is L.C.M. of denominator of m & n.
(ii)
If
xm(a + bxn)pdx
m 1
is an Integer, substitute a + bxn = ts
n
is the denominator of fraction p.
(iii)
m 1
p substitute ax–n + b = ts
n
s is denominator of rational number p.
If
INDEFINITE INTEGRATION