SOLUTION: If {{{m(x)=(5-x)/(x^2-25)}}} then at {{{x=5}}} the graph A. Has a vertical asymptote B. Has an x-intercept C. Has a hole at (5 , 1/10) D. Has a hole at (5 , -1/10) E. None o

Algebra ->  Graphs -> SOLUTION: If {{{m(x)=(5-x)/(x^2-25)}}} then at {{{x=5}}} the graph A. Has a vertical asymptote B. Has an x-intercept C. Has a hole at (5 , 1/10) D. Has a hole at (5 , -1/10) E. None o      Log On


   



Question 957461: If m%28x%29=%285-x%29%2F%28x%5E2-25%29 then at x=5 the graph
A. Has a vertical asymptote
B. Has an x-intercept
C. Has a hole at (5 , 1/10)
D. Has a hole at (5 , -1/10)
E. None of the above

Answer by Edwin McCravy(20055) About Me  (Show Source):
You can put this solution on YOUR website!
m%28x%29=%285-x%29%2F%28x%5E2-25%29

The denominator is not equal to 0:

x%5E2-25%3C%3E0

%28x-5%29%28x%2B5%29%3C%3E0

x-5%3C%3E0, x%2B5%3C%3E0

x%3C%3E5, x%3C%3E-5

So

m%28x%29=%285-x%29%2F%28x%5E2-25%29 where x%3C%3E5, x%3C%3E-5

Get numerator in descending order:

m%28x%29=%28-x%2B5%29%2F%28x%5E2-25%29 where x%3C%3E5, x%3C%3E-5

Factor out -1 in numerator, factor denominator:

m%28x%29=%28-1%28x-5%29%29%2F%28%28x-5%29%28x%2B5%29%29 where x%3C%3E5, x%3C%3E-5

Now if we cancel the (x-5)'s we will have a slightly differen
function, which does have a value at x=5, since the denominator will
not be 0. Let's call it m%5B1%5D%28x%29.  

m%5B1%5D%28x%29=%28-1%28cross%28x-5%29%29%29%2F%28%28cross%28x-5%29%29%28x%2B5%29%29 

m%5B1%5D%28x%29=-1%2F%28x%2B5%29 

There is an asymptote at x=-5 but not at x=5. 

Notice that m%5B1%5D%28x%29=-1%2F%28x%2B5%29 does have a value at x=5, namely, -1%2F%285%2B5%29=-1%2F10

However the original problem m%28x%29=%285-x%29%2F%28x%5E2-25%29 does not have
a value  at x=5

m%28x%29=%285-x%29%2F%28x%5E2-25%29 and m%5B1%5D%28x%29=-1%2F%28x%2B5%29 are identical everywhere
except at x=5.  So there is a hole in m(x) at the point (5,-1/10).  



Edwin