Stuff you MUST know Cold for the AP Calculus Exam in the morning of Wednesday, May 7, 2008. Sean Bird AP Physics & Calculus Covenant Christian High School 7525 West 21st Street Indianapolis, IN 46214 Phone: 317/390.0202 x104 Email: seanbird@covenantchristian.org Website: http://cs3.covenantchristian.org/bird Updated April 24, 2009 Psalm 111:2 Curve sketching and analysis y = f(x) must be continuous at each: dy critical point: = 0 or undefined. And don’t forget endpoints dx d2y dy local minimum: goes (–,0,+) or (–,und,+) or 2 > 0 dx dx d2y dy local maximum: goes (+,0,–) or (+,und,–) or 2 < 0 dx dx point of inflection: concavity changes d2y goes from (+,0,–), (–,0,+), 2 dx (+,und,–), or (–,und,+) Basic Derivatives d sin x cos x dx d cos x sin x dx d 2 tan x sec x dx d 2 cot x csc x dx d n n 1 x nx dx d sec x sec x tan x dx d csc x csc x cot x dx d 1 du ln u dx u dx d u u du e e dx dx d n n 1 Basic Integrals x nx dx d sin x cos x d dx sec x sec x tan x dx d d cos x sin x csc x csc x cot x dx dx d 2 d 1 du tan x sec x ln u dx dx u dx d 2 d u cot x csc x u du e e dx dx dx Some more handy integrals a n 1 ax dx x C n 1 tan x dx ln sec x C n ln cos x C sec x dx ln sec x tan x C More Derivatives d 1 du 1 sin u 2 dx dx 1 u d 1 1 cos x 2 dx 1 x d 1 1 tan x 2 dx 1 x d 1 1 cot x dx 1 x2 d 1 1 sec x 2 dx x x 1 d 1 1 csc x dx x x2 1 d x x a a ln a dx d 1 loga x dx x ln a Recall “change of base” log a x ln x ln a Differentiation Rules Chain Rule d du dy dy du f (u) f '(u) OR dx dx dx du dx Product Rule d du dv (uv) vu OR u ' v uv ' dx dx dx Quotient Rule d u dx v du dx dv v u dx 2 v u ' v uv ' OR 2 v The Fundamental Theorem of Calculus b a f ( x)dx F (b) F (a ) where F '( x) f ( x) d b( x) f ( t ) dt dx a ( x ) Corollary to FTC f (b( x))b '( x) f (a( x))a '( x) Intermediate Value Theorem . If the function f(x) is continuous on [a, b], and y is a number between f(a) and f(b), then there exists at least one number x = c in the open interval (a, b) such that f(c) = y. Mean Value Theorem . If the function f(x) is continuous on [a, b], AND the first derivative exists on the interval (a, b), then there is at least one number x = c in (a, b) f (b) f (a) such that f '(c) ba Mean Value Theorem & Rolle’s Theorem If the function f(x) is continuous on [a, b], AND the first derivative exists on the interval (a, b), then there is at least one number x = c in (a, b) such that f (b) f (a) f '(c) ba If the function f(x) is continuous on [a, b], AND the first derivative exists on the interval (a, b), AND f(a) = f(b), then there is at least one number x = c in (a, b) such that f '(c) = 0. Approximation Methods for Integration Trapezoidal Rule b a f ( x)dx Simpson’s Rule b a 1 ba 2 n [ f ( x0 ) 2 f ( x1 ) ... 2 f ( xn 1 ) f ( xn )] f ( x)dx 1 3 x[ f ( x0 ) 4 f ( x1 ) 2 f ( x2 ) ... 2 f ( xn2 ) 4 f ( xn1 ) f ( xn )] Simpson only works for Even sub intervals (odd data points) 1/3 (1 + 4 + 2 + 4 + 1 ) Theorem of the Mean Value i.e. AVERAGE VALUE If the function f(x) is continuous on [a, b] and the first derivative exists on the interval (a, b), then there exists a number x = c on (a, b) such that b f (c ) a f ( x)dx (b a) This value f(c) is the “average value” of the function on the interval [a, b]. Solids of Revolution and friends L Disk Method a x b R( x) xa V 2 1 f '( x) dx dx Washer Method V b a b R(x) r(x) dx 2 2 General volume equation (not rotated) b V Area ( x) dx a 2 Distance, Velocity, and Acceleration d velocity = (position) average velocity = dt final position initial position d total time (velocity) acceleration = x dt t 2 2 speed = v ( x ') ( y ') * dx dy , dt dt *velocity vector = displacement = tf t o v dt distance = final time initial time v dt tf t o *bc topic ( x ')2 ( y ')2 dt * Values of Trigonometric Functions for Common Angles π/3 = 60° θ sin θ cos θ tan θ 0° 0 1 0 ,30° 6 1 2 3 2 3 3 37° 3/5 4/5 3/4 ,45° 4 53° 2 2 2 2 1 4/5 3/5 4/3 ,60° 3 3 2 1 2 3 ,90° 2 1 0 ∞ π,180° 0 –1 0 π/6 = 30° sine cosine Trig Identities Double Argument sin 2 x 2 sin x cos x cos 2 x cos x sin x 1 2sin x 2 2 2 Trig Identities Double Argument sin 2 x 2sin x cos x 2 2 2 cos 2 x cos x sin x 1 2sin x 1 cos x 1 cos 2 x 2 1 2 sin x 1 cos 2 x 2 2 Pythagorean 2 sin x cos x 1 2 sine cosine Slope – Parametric & Polar Parametric equation Given a x(t) and a y(t) the slope is Polar dy dx dy dt dx dt dy dy / d Slope of r(θ) at a given θ is dx dx / d What is y equal to in terms of r and θ ? x? d r sin d d d r cos Polar Curve For a polar curve r(θ), the AREA inside a “leaf” is 2 1 1 2 r d 2 (Because instead of infinitesimally small rectangles, use triangles) where θ1 and θ2 are the “first” two times that r = 0. r d We know arc length l = r θ and 1 A bh 2 1 1 2 dA rd r r d 2 2 r l’Hôpital’s Rule If then f (a) 0 or g (b) 0 f ( x) f '( x) lim lim xa g ( x) x a g '( x ) Integration by Parts d du dv (uv) vu OR u ' v uv ' dx dx dx We know the product rule L Logarithm d (uv) v du u dv I Inverse u dv d (uv) v du P Polynomial u dv d (uv) v du E Exponential T Trig Antiderivative product rule udv uv vdu (Use u = LIPET) Let u = ln x dv = dx e.g. du = 1 dx v=x ln x dx x x ln x x C Taylor Series If the function f is “smooth” at x = a, then it can be approximated by the nth degree polynomial f ( x) f (a ) f '(a )( x a ) f ''(a ) ( x a)2 2! f ( n ) (a) ( x a)n . n! Maclaurin Series A Taylor Series about x = 0 is called Maclaurin. x 2 x3 x 4 ln( x 1) x 2 3 4 x 2 x3 e 1 x 2! 3! x x3 x5 sin x x 3! 5! x2 x4 cos x 1 2! 4! 1 1 x x 2 x3 1 x