Formulae: Pythagoras theorem: the square of the hypotenuse of a right angle triangle is equal to the sum of the squares on the other two sides. a 2 b2 c 2 Indices 1. a m a n a mn 2. a m a n a mn 3. a m n a mn m n 4. a n a m 1 5. a n n a 6. a 0 1 , a 0. Logarithm 1. log(ab) log a log b a 2. log( ) log a log b b 3. log a n n log a 4. log1 0 Trigonometry Identities: 1 cos 1 2. csc sin 1 cos 3. cot tan sin sin 4. tan cos 1. sec 5. sin 2 cos2 1 6. 1 tan 2 sec2 7. 1 cot 2 cos ec2 Double angle: 1. sin 2 2 sin cos 2. cos 2 cos2 sin 2 2 cos2 1 1 2 sin 2 2 tan 3. tan 2 1 tan 2 Sum and difference of ratio: 1. sin sin 2 sin cos 2 2 2. sin sin 2 cos sin 2 2 3. cos cos 2 cos cos 2 2 4. cos cos 2 sin sin 2 2 Product of ratio: 1. 2 sin cos sin( ) sin( ) 2. 2 cos cos cos( ) cos( ) 3. 2 sin sin cos( ) cos( ) Half angle: 1 1. tan t 2 1 t 2. sin 2 1 t2 1 1 3. cos 2 1 t2 Differentiation: y c cFn sin F cos F tan F sec F csc F cot F dy dx 0 F is a function of x ,c is a constant. y c nF n 1 dF dx dF sin F dx cos F dF dx F ' sec F tan F sec 2 F F ' csc F cot F F ' csc 2 F dy dx sin1 F F' cos1 F 1 F 2 F' tan 1 F cot 1 F 1 F 2 F' 1 F 2 F' 1 F 2 sec1 F F' csc1 F F F 2 1 F' sinh 1 F F F 2 1 F' cosh1 F 1 F 2 F' F 2 1 dF dx 1 dF F dx eF ln F sinh F dF dx dF sinh F dx dF sec h 2 F dx tanh F 2. 3. sec h 1F coth 1 F cosh F cosh F 1. tanh1 F eF Product rule: if u and v are function of x ,then d (uv ) dv du . u v dx dx dx Quotient rule: if u and v are function of x ,then u du dv d( ) v u v dx dx 2 dx v dy dy du Chain rule: If y{u ( x)} ,then dx du dx If u f ( x, y, z) ,then du u dx u dy u dz dt x dt y dt z dt Integration: Integration by parts: udv uv vdu b Area under a curve, A ydx a b Volume formed, V y 2 dx a Mean, M b 1 ydx b a a Root mean square value, (rms) 2 b 1 y 2 dx b a a Complex number 1. z1 z 2 r1 r2 [cos(1 2 ) i sin(1 2 )] z r 2. 1 1 [cos(1 2 ) i sin(1 2 )] z2 r2 3. DeMoivre’s theorem: r (cos i sin ) r n (cos n i sin n) n in 4. e cos n i sin n F' 1 F 2 F' F 1 F 2 F' 1 F 2 in cos n i sin n 5. e 1 6. z 2 cos z 1 7. z n n 2 cos n z 1 8. z 2i sin z 1 9. z n n 2i sin n z Hyperbolic function: e e 1. cosh 2 e e 2. sinh 2 e e 3. tanh e e Vectors If P ( a i b j c k ) then magnitude of P is r a 2 b 2 c 2 a b c Direction cosine of is given by: l , m , n and l 2 m2 n 2 1 r r r Dot product of vector a and vector b is ( a . b ) a b cos Angle between two vectors is cos ll 'mm'nn' For perpendicular vectors, ll ' mm' nn' 0 A straight line through A parallel the free vector b is r a b where r x i y j z k , b b1 i b2 j b3 k and a a1 i a2 j a3 k x a1 y a2 z a3 Vector equation in Cartesian form is b1 b2 b3 Series Arithmetic series: a (a d ) (a 2d ) (a 3d ) un a (n 1)d n S [ 2 a ( n 1) d ] 2 Geometric series : a ar ar 2 ar 3 un ar n1 Sn If a(1 r n ) 1 r r 1, S a 1 r Power of natural numbers: n n(n 1) 1. r 2 r 1 n r 2. r 1 2 n(n 1)(2n 1) 6 n( n 1) r3 2 r 1 n 3. 2 Maclaurin’s series: x2 x3 f ( x) f (0) xf ' (0) f " (0) f ' ' ' (0) 2! 3! Taylor’s series for one variable: h2 h3 f ( x h) f ( x) hf ' ( x) f " ( x) f ' ' ' ( x) 2! 3! Taylor’s series of two variables: f ( x, y ) near the point ( xo , yo ) is f ( x, y ) f ( x0 , y0 ) ( x x0 ) f x ( x0 , y0 ) ( y y0 ) f y ( x0 , y0 ) 1 ( x x0 ) 2 f xx ( x0 , y0 ) 2( x x0 )( y y0 ) f xy ( x0 , y0 ) ( y y0 ) 2 f yy ( x0 , y0 ) ... (1) 2! Binomial series: ( a b ) n a n na n 1b n ( n 1) n 2 2 n ( n 1)( n 2) n 3 3 a b a b b n 2! 3! Standard series: x3 x5 x7 sin x x 3! 5! 7! x2 x4 x6 cos x 1 2! 4! 6! x 2 x3 x 4 x e 1 x 2! 3! 4!