Register to reply

AP test problems, Derivatives and Tangent lines

by chris40256
Tags: derivatives, lines, tangent, test
Share this thread:
chris40256
#1
Nov29-07, 03:49 PM
P: 5
1. The problem statement, all variables and given/known data
Let f be the function given by f(x) = (2x-5)/(x^2-4).
a.Find the domain of f.
b.Write an equation for each vertical and each horizontal asymptote for the graph of f.
c.Find f'(x).
d.Write an equation for the line tangent to the graph of f at the point (0,f(0)).

3. The attempt at a solution
Note: Just checking answers!
a.domain: x does not equal 2 or -2 because those values of x make the denominator 0
b. vertical asymptote
x = 2, x = -2
horizontal asymptote
as x goes to positive or negative infinity
f(x) goes to 0
y = 0

c. f'(x) = (2(x^2 - 4) - (2x - 5)(2x))/(x^2-4)^2
= (2x^2 - 8 - 4x^2 + 10x)/(x^2-4)^2
= -2(x^2 - 5x + 4)/(x^2-4)^2
= -2(x-4)(x-1)/(x^2-4)^2
f(0) = -5/(-4) = 5/4

d. y - 5/4 = slope (x - 0)
slope = f'(0) = -2(-4)(-1)/(-4)^2 = -8/16 = -1/2
y - 5/4 = (-1/2)x
y = (-1/2)x + 5/4
Phys.Org News Partner Science news on Phys.org
World's largest solar boat on Greek prehistoric mission
Google searches hold key to future market crashes
Mineral magic? Common mineral capable of making and breaking bonds

Register to reply

Related Discussions
Tangent lines Calculus & Beyond Homework 7
Tangent lines to a f(x) Calculus & Beyond Homework 5
Tangent Lines Introductory Physics Homework 2
Tangent Lines Introductory Physics Homework 2
Tangent lines Introductory Physics Homework 8