x = a sinb if rad(a^2 - x^2) is in the integrandx = a tanb if rad(a^2 + x^2) is in the integrandx = a secb if rad(x^2 - a^2) is in the integrand
9.4 Integrls of Rational Functions
Use partial fractions then evaluate integral
9.5 Integrals with Quadratic Expressions
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1. Look for a quadratic equation in the integrand. 2. Complete the square.3. a. set u = the perfect square from the completed square b. solve for x using u.4. plug in u accordingly and and x as well5. evaluate integral
9.6 Other substitution tricks
Chapter 7: Inverses, Ln, e
7.1: Inverses
1-1 Functions
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1 - 1 functions are functions that never takes the same value twice.More formally:1. Let f be a function that maps from D -> R2. For every x in D, there exist a unique R. - Let x1, x2 be in D - f(x1) is not = f(x2)NOTE: A) #2 implies the converse: for every y in R, there exist a unique x in DB) Graphically, a function is 1 - 1 if a horizontal line never intersects the function's curve twice.
Every increasing/decreasing function is 1 - 1
Inverse Function
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The inverse of a function that maps from D -> R is the function that maps from R -> D.Let y = f(x) be a 1 - 1 function that maps from D - > R. A function g is the inverse of f where the R(f) = D(g) and D(f) = R(g). Therefore, y = f(x) <=> x = g(y) The inverse function g is denoted as f^-1
g(f(x)) = x; f(g(x)) = y
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If g is the inverse of f, then... i) g(f(x)) = x for every x in D(f) ii) f(g(x)) = x for every x in R(f)-------------------Ver1 proof is set as hyperlinkVer2 proof URL: http://i1321.photobucket.com/albums/u556/radicaldreamer18/Calculus%202%20Chapter%207/IMAG0299_zps9a60cf31.jpg
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Derivative of an inverse fn.
7.2: Logarithms
Definition of natural log
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The natural logarithmic function is a logarithm with base e. In addition, it is also found that...ln(x) = integral {(1/t) dt} from 1 -> x----------------------If x > 1, ln(x) = integral {(1/t) dt} from 1 -> xIf 0 < x < 1, -ln(x) = integral {(1/t) dt} from x -> 1
(d/dx) ln(x) = 1/x
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Shortcut proof:1. By defn of ln's, ln(x) = integral {(1/t) dt} from 1 -> x.2. ln(x) must be differentiable because it is the antiderivative of something (1/t)3. (d/dx) ln(x) = (d/dx) integral {(1/t) dt} from 1 -> x4. (d/dx) ln(x) = 1/x, the derivative of an integral of a function is the function itself. -----------------------------(d/dx) ln(u) = (1/u)duproof:1. let y = f(x) = ln(u)2. (dy/dx) = (dy/du)(du/dx) 3. f'(x) = (d/du) ln(u) * du
(d/dx) ln(u) = u'/u
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integral of (1/u) du = u'/u; given that u is a function. Proven from chain rule of (d/dx) ln(x)(d/dx) ln(u) = (d/du) ln(u) * (du/dx) = (1/u)du
integral of ln(x)
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Derived using integration by parts!!!
Ptoperties of logarithms
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1. log base x of x => ln(e) = 12. log(a) + log(b) = log(ab)3. log(a) - log(b) = log(a/b)4. a log(b) = log(b^a)----------------More basic stuff: log base a of y = x, then y = a^x
Logarithmic Differentiation Guildelines
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Given a differentiable equation, do the following to differentiate logarithmically:1. Take ln of both sides2. Differentiate both sides...IMPLICIT DIFFERENTIATION MAY BE NEEDED ALONG THE WAY3. Multily by the initial equation.
7.3: The letter e
Definition of e
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e is a positive number where ln(e) = 1 <=> e is the base of ln(x)