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. INDEFINITE INTEGRATION 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 INDEFINITE INTEGRATION 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 INDEFINITE INTEGRATION 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. INDEFINITE INTEGRATION 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