Formulas Geometry: Circles: Area = r2 Circumference = 2 r 4 Spheres: Volume = 3 r3 Surface Area = 4 r2 Cylinders: Volume = (Area of base) (Height) 1 Cones: Volume = 3 (Area of base) (Height) Trigonometric Identities: sin2x + cos2x = 1 tan2x + 1 = sec2x ctn2x + 1 = csc2x sin(x+y) = sin x cos y + cos x sin y cos 2x = cos2x - sin2x sin 2x = 2 sin x cos x sin x sin y = cos(x-y) - cos(x+y) 2 sin x cos y = sin(x+y) + sin(x-y) 2 y = cos(x+y) = cos x cos y - sin x sin y cos x cos y = sin2x = is that angle y such that x = sin-1x cos-1x tan-1x cot-1x sec-1x csc-1x 1 - cos(2x) 2 cos(x-y) + cos(x+y) 2 cos2x = - 2 y 2 0y - < y < and 0 < y < 0 y < or y < 0 < y or < y sin y cos y tan y cot y sec y csc y 2 2 2 2 sin-1(- x) = - sin-1 x Hyperbolic Functions: ex – e-x sinh x = 2 cosh x ex + e-x coth x = sinh x = ex - e-x cosh2x - sinh2x = 1 cos-1x = 2 - sin-1x ex + e-x 2 1 2 sech x = cosh x = ex + e-x cosh x = tanh2x + sech2x = 1 3 2 3 2 cos-1(- x) = - cos-1x sinh(x+y) = sinh x cosh y + cosh x sinh y 1 + cos(2x) 2 sinh x ex - e-x tanh x = cosh x = ex + e-x 1 2 csch x = sinh x = ex - e-x coth2x = 1 + csch2x cosh(x+y) = cosh x cosh y + sinh x sinh y cosh 2x = cosh2x + sinh2x sinh 2x = 2 sinh x cosh x sinh2x = y = cosh(2x) - 1 2 cosh2x = = sinh-1x cosh-1x tanh-1x coth-1x sech-1x csch-1x cosh(2x) + 1 2 is that y such that x = ln(x + x2 + 1) ln(x + x2 -1) 1 ln( 11 +- xx ) 2 1 2 ln( xx +1 ) -1 ln1 + 1 - x2 x ln1 + x2 + 1 x sinh y cosh y and y 0 tanh y coth y sech y and y 0 csch y Derivatives dy = dx f(x+h) - f(x) h h0 f’(x) = lim Linear approximation (3 ways of writing the same thing) f(x) f(xo) + f’(xo)(x-xo) f(x+x) f(x) + f’(x) x y dy dx x Quadratic approximation f”(xo) f”(xo) f(x+x) f(x) + f’(x) x + 2 (x)2 f(x) f(xo) + f’(xo)(x-xo) + 2 (x-xo)2 y dy dx x + 1 d2y 2 dx2 (x)2 Mean Value Theorem (Slope of secant line = slope of tangent line at intermediate point. Same as linear approximation but uncertainty is where derivative is evaluated.) f(x) = f(xo) + f’(c)(x-xo) f(x+x) = f(x) + f’(c) x f(x) lim g(x) = L’Hospital’s Rule xc f '(x) lim g'(x) xc y x dy dx (c) provided f(x) and g(x) are either both 0 or both Summation Formulas n(n+1) 1 + 2 + 3 + ... + n = 2 n2(n+1)2 13 + 23 + 33 + ... + n3 = 4 n(n+1)(2n+1) 12 + 22 + 32 + ... + n2 = 6 n+1 x -1 1 + x + x2 + ... + xn = x-1 Integrals n b f(x) dx = lim n a b-a n ] n f[a + k(b-a) k=1 b Area = L(x) dx L(x) = Length of cross section through x. a 2 b Volume = A(x) dx A(x) = Area of cross section through x. a b 2 2 Volume = [f(x) - g(x) ] dx For the solid created by rotating a region about the x axis. The a region is bounded above by y = f(x), below by y = g(x), on the left by x = a and on the right by x = b. b Volume = 2 x[f(x) - g(x)] dx For the solid created by rotating the same region about the y a axis. b Work = F(x) dx F(x) = Force on object at position x. a Table of Derivatives and Integrals d 2 dx tan x = sec x d 2 dx cot x = - csc x d dx sec x = tan x sec x d dx csc x = - cot x csc x d x x dx a = a ln(a) d 1 -1 dx sin x = 1 - x2 2 sec x dx = tan x d -1 dx cos x = 1 dx = - cos-1x 1 - x2 1 dx = tan-1x 1 + x2 -1 1 - x2 d 1 -1x = tan dx 1 + x2 d -1 -1 dx cot x = 1 + x2 2 csc x dx = - cot x tan x sec x dx = sec x cot x csc x dx = - csc x ax x a dx = ln(a) 1 dx = sin-1x 1 - x2 d 1 -1x = sec dx x x2 - 1 1 dx = - cot-1x 1 + x2 1 x x2 - 1 dx = sec-1x d -1 -1 dx csc x = x x2 - 1 1 x x2 - 1 dx = - csc-1x d dx sinh x = cosh x cosh x dx = sinh x 3 d dx cosh x d dx tanh x d dx coth x d dx sech x d dx csch x = sinh x sinh x dx = cosh x = sech2 x 2 sech x dx = tanh x = - csch2 x 2 csch x dx = - coth x = - tanh x sech x tanh x sech x dx = - sech x = - coth x csch x coth x csch x dx = - csch x d -1 dx sinh x = 1 1 + x2 d -1 dx cosh x = 1 x2 - 1 1 1 + x2 dx = sinh-1x 1 dx = cosh-1x 2 x -1 d 1 -1 dx tanh x = 1 - x2 d -1 -1x = sech dx x 1 - x2 1 dx = tanh-1x 1 - x2 1 dx = coth-1x 1 - x2 1 x 1 - x2 dx = - sech-1x d -1 -1x = csch dx x x2 + 1 1 dx = - csch-1x x x2 + 1 d 1 -1 dx coth x = 1 - x2 More Integrals u dv = uv - v du sec x dx = ln( tan x + sec x) csc x dx = ln( csc x - cot x) 1 n n-1 sin x dx = - n sin x cos x n cos x dx = n tan x dx = cotnx dx = n sec x dx = n csc x dx = 1 cosn-1x sin x n 1 tann-1x n-1 1 - n-1 cotn-1x 1 tan x secn-2x n-1 1 - n-1 cot x cscn-2x + + n-1 sinn-2x dx n n-1 cosn-2x dx n - n-2 tan x dx - cotn-2x dx n-2 n-2 + n-1 sec x dx n-2 n-2 + n-1 csc x dx n 2m+1 n 2 m 2 2 dx = sin x cos u (1-u ) du after substituting u = sin x and using cos x = 1 – sin x Similarly when sin is to an odd power 4 2n 2m sin x cos dx Use sin2x = 1 - cos(2x) 2 and cos2x = 1 + cos(2x) 2 n 2m n 2 m-1 2 2 tan x sec dx = u (1+u ) du after substituting u = tan x and using sec x = 1 + tan x 2n+1 m 2 n m-1 2 2 tan x sec dx = (u -1) u du after substituting u = sec x and using tan x = sec x - 1 2n 2m+1 2 n 2m+1 dx = dx after tan2x = sec2x – 1. Now expand out and use tan x sec (sec x - 1) sec n reduction formula for sec x dx Integral involving a2 – x2 Let x = a sin u Integral involving a2 + x2 Let x = a tan u Integral involving x2 – a2 Let x = a sec u b 4ac - b2 a(x + )2 + . 2a 4a Integral involving ax2 +bx + c Complete the square: ax2 +bx + c = b Then substitute u = x + 2a which reduces the integral to one of the three previous anxn + an-1xn-1 + + a1x + a0 Integral of a rational function dx. First, divide denominator into m m-1 bmx + bm-1x + + b1x + b0 numerator to get a polynomial plus a rational function where the numerator has degree less than the denominator. Integrate the polynomial as usual. For the new rational function, factor the denominator into the product of linear and quadratic factors and split it up using partial fractions: anxn + an-1xn-1 + + a1x + a0 A1 A2 B C Dx + E = x-r + x-r + + x-s + (x-s)2 + x2+bx+c. To find the numerators, 2 2 1 2 (x-r1)(x-r2) (x-s) (x +bx+c) cross multiply to get anxn + an-1xn-1 + + a1x + a0 = A1(x-r2)(x-s)2(x2+bx+c) + A2(x-r1)(x-r3)(x-s)2(x2+bx+c) + + B(x-r1)(x-r2)(x-s)(x2+bx+c) + C(x-r1)(x-r2)(x2+bx+c) + (Dx+E)(x-r1)(x-r2)(x-s)2. You will need to plug in additional values to find B, D and E. 1 A1 A2 Example: (x-4)(x-5) = x-4 + x-5 1 = A1(x-5) + A2(x-4). x = 4 A1 = -1. The resulting fractions with linear denominators are easy to integrate. Complete the square, if necessary, to integrate the ones with quadratic denominators. b b b lim f(x) dx = b f(x) dx lim f(x) dx = a- f(x) dx lim f(x) dx = ca+ f(x) dx if f(x) is unbounded as x a a b a b a a - 0 f(x) dx = f(x) dx + f(x) dx - - 0 c Numerical Integration Midpoint method b f(x) dx 2(x) [ f(x1) + f(x3) + f(x5) + + f(xn-1) ] where x = b-a and xj = a + j(x) and n is even n a Simpson’s method b x f(x) dx 3 [ f(x0) + 4f(x1) + 2f(x2) + 4f(x3) + 2f(x4) + a 5 + 2f(xn-2) + 4f(xn-1) + f(xn) ] with x, xj as above, n is even Arc Length b L = length of curve y = f(x) where a x b = 2 dy 1 + dx dx a Center of Mass _ _ (x, y) = center of mass of thin plate of uniform density occupying the region bounded above by y = f(x) and below y = g(x) and between x = a and x = b. Let A = area. Then _ _ 1 b 1 b 2 2 x = A x [f(x) g(x)] dx y = 2A {[f(x)] - [g(x)] } dx a a Parametric Equations of Curves: x = f(t) and y = g(t) To write as y = F(x): Solve x = f(t) for t in terms of x and substitute in y = g(t). Similarly to write as x = G(y) Slopes: dy dx = dy dt dx dt Second derivatives: b a d2y d2x = d dy ( ) dt dx dx dt Areas: y dx = g(t) f ′(t) dt where a = f() and b = f() Arc Lengths: L = 2 2 dx dy + dt dt dt = length of the part corresponding to t Polar Coordinates r and x2 + y2 y tan = x Curve defined by a polar equation r = f(): x = f() cos and y = f() sin r = x = r cos y = r sin dr sin + r cos dy d Slopes: dx = dr cos - r sin d Arc Lengths: L = 1 2 dr r2 + d = length of the part corresponding to t d 2 2 Areas: A = 2 {[f()] - [g()] } d = area of region where g() r f() and 6 Conic Sections y (x - u) a2 Ellipse: 2 + (y - v) b2 2 b = 1 a b foci at (u c, v) c2 = a2 – b2 a x a y y b Hyperbola: (x - u)2 (y - v)2 - b2 a2 foci at (u c, v) = 1 bx a a x a c2 = a2 + b2 y bx a Sequences and Series Geometric series: 1 xn = 1 - x if -1 < x < 1 n=0 nth term test: lim an 0 an diverges n n=1 n=1 n=1 1 n=1 | an | < an converges Absolute convergence: Integral test: f(x) positive & decreasing f(x) dx < f(n) < Limit comparison test: Assume an > 0 & bn > 0 for all n n=1 n=1 an n bn < & bn < an < an lim n bn > 0 & bn = an = lim n=1 n=1 Ratio test: an+1 n an If an > 0 then | an+1 | lim n |an | lim < 1 an < & n=1 < 1 an converges an+1 n an lim > 1 an = n=1 | an+1 | lim n |an | & n=1 > 1 an diverges n=1 Root test: n If an > 0 then n lim n n an < 1 an < lim n & lim n n=1 an > 1 an = n=1 n | an | < 1 an converges & lim n n=1 | an | > 1 an diverges n=1 Alternating series test: an decreasing with n & lim an = 0 (-1)nan converges n n=1 Taylor series: f(x) = f(n)(a) (x - a)n n! n=0 f(x) - n f(j)(a) (x - a)j < M |x - a|n+1 j! (n+1)! j=0 where M = maximum of | f(n+1)(t) | for t between a and x 7