Author 
Message 
yclicc New poster
Post Number: 1
 Posted on Tuesday, 24 April, 2012  08:35 pm:  
[display]f(x)=x4\frac{16(2x+1)^2}{x^2 * (x+4)}[/display] State vertical and oblique asymptotes (x=0,4, y=x) and show that the oblique asymptote is tangent to the curve. I have tried proving it is tangent by setting f(x)=x and trying to show there is a repeated root, but I get a horrible cubic: x^3+20x^2+16x+4=0 . Then, when I cheat and type the equation into wolfram alpha, it appears part 2, show that f(x)=0 has a double root, isn't true... http://www.admissionstests.cambridgeassessment.org.uk/adt/digitalAssets/107041_2004.zip is the link to the paper...can anyone offer any suggestions? 
biffboy Regular poster
Post Number: 67
 Posted on Wednesday, 25 April, 2012  07:10 am:  
Your working suggest the asymptote isn't y=x 
Andre Rzym Veteran poster
Post Number: 1796
 Posted on Wednesday, 25 April, 2012  12:19 pm:  
Either one of your stated vertical asymptotes is incorrect, or your original statement of [inline]f(x)[/inline] has a typo (and [inline]y=x[/inline] is not quite the oblique asymptote). Andre 
Rahulllll Poster
Post Number: 7
 Posted on Wednesday, 25 April, 2012  07:28 pm:  
seems like you took your oblique asymptote as y=x which isnt completely accurate. look at the way f(x) has been written again it is giving you a big hint. 
