typed by Sean Bird, Covenant Christian High School updated April 6, 2006 Curve sketching and analysis y = f(x) must be continuous at each: dy critical point: = 0 or undefined dx or endpoints local minimum: dy goes (–,0,+) or (–,und,+) or d 2 y >0 dx 2 dx local maximum: 2 dy goes (+,0,–) or (+,und,–) or d y <0 dx 2 dx point of inflection: concavity changes d 2 y goes from (+,0,–), (–,0,+), dx 2 (+,und,–), or (–,und,+) Basic Derivatives d n x nx n1 dx d sin x cos x dx d cos x sin x dx d tan x sec2 x dx d cot x csc2 x 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 du e eu dx dx AP CALCULUS Stuff you MUST know Cold Differentiation Rules Chain Rule d du dy dy du f (u) f '(u) OR dx dx dx du dx * means topic only on BC Approx. Methods for Integration Trapezoidal Rule b a f ( x)dx d du dv (uv) vu OR u ' v uv ' dx dx dx 2 f ( xn 1 ) f ( xn )] b a f ( x)dx 1 3 x[ f ( x0 ) 4 f ( x1 ) 2 f ( x2 ) ... 2 f ( xn2 ) 4 f ( xn1 ) f ( xn )] Quotient Rule d u dx v [ f ( x0 ) 2 f ( x1 ) ... Simpson’s Rule Product Rule du dx 1 ba 2 n v u v2 dv dx OR u ' v uv ' v2 “PLUS A CONSTANT” The Fundamental Theorem of Calculus 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 f (c ) b a b a f ( x)dx F (b) F (a ) where F '( x) f ( x) Corollary to FTC d b( x) f (t )dt dx a ( x ) 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 . (b a) This value f(c) is the “average value” of the function on the interval [a, b]. Solids of Revolution and friends Disk Method V x b xa R( x) 2 dx Washer Method V b a R(x) r(x) dx 2 2 General volume equation (not rotated) b V Area ( x) dx a *Arc Length L 1 f '( x) dx b 2 a b a More Derivatives d 1 du sin 1 u 2 dx dx 1 u d 1 cos1 x dx 1 x2 d 1 tan 1 x dx 1 x2 d 1 cot 1 x dx 1 x2 d 1 sec1 x dx x x2 1 d 1 csc1 x dx x x2 1 d x a a x ln a dx d 1 loga x dx x ln a Mean Value Theorem f ( x)dx x '(t ) y '(t ) dt 2 2 Distance, Velocity, and Acceleration velocity = d (position) dt 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 acceleration = *velocity vector = 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 . dx dy , dt dt speed = v ( x ')2 ( y ')2 * displacement = Rolle’s Theorem d (velocity) dt distance = tf t v dt o final time initial time v dt tf t ( x ')2 ( y ')2 dt * o average velocity = final position initial position total time x = t BC TOPICS and important TRIG identities and values l’Hôpital’s Rule f (a) 0 or , If g (b) 0 f ( x) f '( x) lim then lim x a g ( x) x a g '( x ) Euler’s Method If given that dy dx f ( x, y ) and that the solution passes through (xo, yo), y ( xo ) yo y ( xn ) y ( xn1 ) f ( xn1 , yn1 ) x In other words: xnew xold x ynew yold Slope of a Parametric equation Given a x(t) and a y(t) the slope is dy dy dt dx dx dt 2 1 r d 4 If the limit equal 1, you know nothing. Lagrange Error Bound If Pn ( x) is the nth degree Taylor polynomial of f(x) about c and f ( n1) (t ) M for all t between x and c, then M n1 xc n 1 ! Alternating Series Error Bound N If S N 1 an is the Nth partial sum of a n k 1 convergent alternating series, then S S N aN 1 Geometric Series a ar ar 2 ar 3 ar n 1 ar n 1 a if |r|<1 1 r This is available at http://cs3.covenantchristian.org/bird/Smart/Calc1/StuffMUSTknowColdNew.htm cos θ 1 3 2 4/5 2 2 3/5 1 2 tan θ 0 1 0 “ ” 3 3 3/4 1 4/3 3 0 1 1 cos 2 x 2 Pythagorean sin 2 x cos2 x 1 (others are easily derivable by dividing by sin2x or cos2x) 1 tan 2 x sec2 x sin 2 x cot 2 x 1 csc2 x Reciprocal 1 sec x or cos x sec x 1 cos x 1 csc x or sin x csc x 1 sin x Odd-Even sin(–x) = – sin x (odd) cos(–x) = cos x (even) Some more handy INTEGRALS: tan x dx ln sec x C ln cos x C n 1 diverges if |r|≥1; converges to sin θ 0 1 2 3/5 2 2 4/5 3 2 0 1 Trig Identities Double Argument sin 2 x 2sin x cos x cos 2 x cos2 x sin 2 x 1 2sin 2 x 1 cos 2 x 1 cos 2 x 2 ak 1 1 ak f ( x) Pn ( x) ,60° ,90° 2 π,180° k 0 u=LIPET) k ,45° 53° 3 The series ak converges if lim ,30° 37° 2 dy dy / d dx dx / d d r sin d d d r cos Ratio Test Use IBP and let u = ln x (Recall 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 ex 1 x 2! 3! 2 x x4 cos x 1 2! 4! x3 x5 sin x x 3! 5! 1 1 x x 2 x3 1 x x 2 x3 x 4 ln( x 1) x 2 3 4 1 2 6 where θ1 and θ2 are the “first” two times that r = 0. The SLOPE of r(θ) at a given θ is Integral of Log ln x dx x ln x x C Polar Curve Integration by Parts θ 0° For a polar curve r(θ), the AREA inside a “leaf” is dy x dx xold , yold udv uv vdu Values of Trigonometric Functions for Common Angles sec x dx ln sec x tan x C