Sunday
March 29, 2015

Homework Help: cal

Posted by cal on Friday, October 25, 2013 at 9:25am.

Determine all values of x, (if any), at which the graph of the function has a horizontal tangent.

y(x) = 6x/(x-9)^2

when i workout this problem I get this:

by quotient rule:

dy/dx = ( (x-9)^2 (6) - 6x(2)(x-9))/(x-9)^4
= 0 at a horizontal tangent

6(x-9)^2 - 12x(x-9) = 0
6(x-9)[x-9 - 2] = 0
6(x-9)(x-11) = 0
x=9 or x=11 , but x≠9 , there is a vertical asymptote at x=9

x = 11

but I have these answer choices to choose from:

A. x=9 and x=6

B. x=-9

C. x=-9 and x=6

D. x= 6

E. The graph has no horizontal tangents.

is it E then

Answer this Question

First Name:
School Subject:
Answer:

Related Questions

cal - Determine all values of x, (if any), at which the graph of the function ...
Calculus - Functions? - #1. A cubic polynomial function f is defined by f(x) = ...
AP CALC. AB - Let h be a function defined for all x≠0 such that h(4)=-3 ...
calculus (derivativs) - Find the points on the graph of f where the tangent line...
Calculus (derivatives) - Find the points on the graph of f where the tangent ...
Calculus - Let f be a twice-differentiable function defined on the interval -1.2...
cal - find the equation of a quadratic function whose graph is tangent at x=1 to...
calculus - 1. Which of the following expressions is the definition of the ...
math - 1. find the equation of the tangent line at x=1 to y=f(x) where f(x)=(3x^...
math - 1. find the equation of the tangent line at x=1 to y=f(x) where f(x)=(3x^...

Members