Unit 7 Flashcards
POWER-REDUCING FORMULAS
sin^2 θ =
1-cos(2θ) / 2
cos^2 θ =
1+cos(2θ) / 2
tan^2 θ
1-cos(2θ) / 1+cos(2θ)
INVERSE TRIG INTEGRATION
∫ du / (a^2 - u^2)^1/2 =
arcsin(u/a) + C
∫ du / a^2 + u^2 =
1/a arctan(u/a) + C
∫ du / u(u^2 - a^2)^1/2 =
1/a arcsec(|u|/a) + C
TRIG. INTEGRATION
∫ tanx dx =
ln|secx| + C
∫ cotx dx =
ln|sinx| + C
∫ secx dx =
ln|secx + tanx| + C
∫ cscx dx =
ln|cscx - cotx| + C
u-substitution
make sure to evaluate EVERYTHING in terms of u
INTEGRATION BY PARTS
- ultraviolet voodoo / tabular method
∫ u dv = uv - ∫ v du
- use when it seems like the function can’t be integrated
for ultraviolet voodoo, choose u in this order:
- inverse trig.
- polynomial
- exponential
- trig.
(make the part that’s easiest to integrate dv)
complete the square
watch a video
TRIG. SUBSTITUTION WITH RADICALS
either in the form
- (a^2 - u^2)^1/2 (adjacent side)
- (u^2 - a^2)^1/2 (opposite side)
- (u^2 + a^2)^1/2 (hypotenuse)
- find x, dx, and the radical by putting the other sides over the constant
- look up examples
PARTIAL FRACTION DECOMPOSITION
- factor denominator, then split into parts
- make sure if part has a power higher than one, make numerator in terms of that
- ex. (Cx+D) / (x^2 + 4)
IMPROPER INTEGRALS
∞ b
∫ f(x) dx = lim ∫ f(x) dx
a b->∞ a
- if you get a value, it converges (reaches a distinct value)
- if you get DNE, it diverges (continues to grow without bounds)
for a limit as x approaches infinity, if the higher power is in the _____
- denominator: limit = 0
- numerator: limit => DNE
- equal powers: limit = coefficients
ln(∞) =>
∞
ln(-∞) =>
DNE
e^∞ =>
∞