Friday, October 7, 2016

Calculus: Early Transcendentals, Chapter 4, Review, Section Review, Problem 25

y=x^2/(x+8)
a) Asymptotes
Vertical asymptotes are the zeros of the denominator
x+8=0rArrx=-8
Vertical asymptote is x=-8
Degree of numerator=2
Degree of denominator=1
Degree of numerator=1+Degree of denominator, so the asymptote is a slant asymptote of the form y=mx+b
For a rational function the slant asymptote is the quotient of the polynomial division.
x^2/(x+8)=x-8+64/(x+8)
the slant asymptote is y=x-8
b) Maxima/Minima
y'=((x+8)2x-x^2)/(x+8)^2
y'=(2x^2+16x-x^2)/(x+8)^2
y'=(x(x+16))/(x+8)^2
Let's find critical numbers by solving x for y'=0,
x(x+16)=0rArrx=0 , x=-16
y(-16)=(-16)^2/(-16+8)=-32
y(0)=0^2/(0+8)=0
Local maximum=-32 at x=-16
Local minimum=0 at x=0
c) Inflection points
y''=((x+8)^2(2x+16)-(x^2+16x)(2)(x+8))/(x+8)^4

y''=(2x^2+16x+16x+128-2x^2-32x)/(x+8)^3
y''=128/(x+8)^3
128/(x+8)^3=0
there is no solution for x , so there are no inflection points.

No comments:

Post a Comment

Why is the fact that the Americans are helping the Russians important?

In the late author Tom Clancy’s first novel, The Hunt for Red October, the assistance rendered to the Russians by the United States is impor...