|
Question 156953: Stan is so good i had to come back for more.
1)Given the function y=2x-3/x-1 what are the
a)x intercept
b)y intercept
c)vertical asymptote(s)
d)horizontal asymptote(s)
e)slant asymptote
2)For the function f(x)=x^2(x-2)
a)find the X intercepts and for each intercept indicate whether the graph of F crosses (c) or merely touches (t)the X axis at each intercept.
b)find the Y intercept
c)Over what interval is f>0?
Answer by jim_thompson5910(35256) (Show Source):
You can put this solution on YOUR website! I'll do the first one to get you going in the right direction
1)
a) x intercept
The x-intercept occurs when .
Start with the given equation
Plug in
Multiply both sides by
Multiply 0 and to get 0
Add 3 to both sides.
Divide both sides by 2
So the answer is which means that the x-intercept is , which is (1.5, 0). Note: the x-intercept is in the form of (x, 0)
------------------------------------
b)y intercept
The y-intercept occurs when
Start with the given equation
Plug in
Multiply
Subtract
Reduce
So the answer is which means that the y-intercept is Note: the y-intercept is in the form of (0, y)
----------------------------------------
c)vertical asymptote(s)
To find the vertical asymptote, just set the denominator equal to zero and solve for x (remember you CANNOT divide by zero)
Set the denominator equal to zero
Add 1 to both sides
Combine like terms on the right side
So the vertical asymptote is
-------------------------------------------
d)horizontal asymptote(s)
Since the degree of the numerator and the denominator are the same, we can find the horizontal asymptote using this procedure:
To find the horizontal asymptote, first we need to find the leading coefficients of the numerator and the denominator.
Looking at the numerator , the leading coefficient is
Looking at the denominator , the leading coefficient is
So the horizontal asymptote is the ratio of the leading coefficients. In other words, simply divide by to get
So the horizontal asymptote is
-------------------------------------------------
e) slant asymptote
Since horizontal asymptote exists, there isn't a slant asymptote (you either have one or the other, but not both)
--------------------------------------------------
Notice if we graph , we can visually verify our answers:
Graph of with the x-intercept (or the point (1.5, 0)), the y-intercept (0,3), the horizontal asymptote (blue line) and the vertical asymptote (green line)
--------------------------------------------------
With this info, you should have a better understanding on how to approach # 2. If you're still having trouble with # 2, then repost the question.
|
|
|
| |