asymptotes, min. & max.

[jenny_calc]

Hi guys,

i'm stuck with 2 questions that are due today and can't solve them or find a way to solve them, so please if somebody could help me out.

1. if f(x)=x^2 - 3x + 2
----------------
x^2

a. find x and y intercepts
b. vertical asymptotes and direction
c. horizontal asymptote
d. f ' and intervals of increase and decrease and relative extrema
e. f'' and intervals of concavity and points of inflection


2. 20 ft. of wire is to be used to form a circle and a square. How should the wire be cut so that the total enclosed area is a maximum? minimum?


** I will be thankful if anyone could help me with them.

thanks a lot!!!

 

[tkhunny]

Those are pretty straight-forward. Where are you stuck? Do you know anything about Rational Functions?

 

[deniz_hal]

well i got a and b (part) i can't do the directions and horizontal asymptotes...I'm bad actually with rational functions

 

[tkhunny]

I suggest very strongly that you get better at Rational Functions before you tackle calculus. Fortunately, however, much of the rest of your class is probably in the same boat.

Horizontal asymptotes shouldn't scare you. Just look at the degree of numerator (N) and denominator (D) separately.

D > N ==> y = 0
D = N ==> y = {ratio of leading coefficients}
D = N-1 ==> y = mx+b {Long division gives the oblique asymptote}
D < N-1 ==> Long division gives the higher-order anymptote

What's next?

 

[deniz_hal]

well, i got;
1.a) x-int => y=0, then, x2-3x+2/(x2)=0 => (x-2)(x-1)/(x2)= 0, x =/= 0


x=2 and x=1

y-int =>, x=0, then, (0)2-3(0)+2/(0)2 ~ undef.

b) x2 = 0
x = 0 => vertical asymptote.

and that's how far I could do Sad

I really bad with rational functions

 

[tkhunny]

Really, go pratice your rational functions. GET better. It won't come by magic.