- #1
DDRchick
- 27
- 0
Find an equation of a rational function f(x)that satisfies the conditions. We're allowed to use a calculator, by the way. (:
Okay, conditions:
vertical asymptote: x=-5, x=0
Horizontal asymptote: y=0
x-intercept=7; f(1)=4
On the test i had no idea how to do it, but after seeing her key,I somewhat understand. I looked in the textbook and was able to see where many things came from.
a(x-7)/(x+5)(x)
for one, i have no idea where the a and the x came from. I do, however, understand that the (x-7) is from the x-int. and that the (x+5) is from the v.a.
4=a(1-7)/(1+5)(x) again, no idea where the a and x came from. I see that 4=f(1) which means that y=4 and x=1.
4=a(-6)/(6)(1)
I understand she plugged in that last x finally with a 1 and simplified everything else.
4=-a, a=-4
f(x)=-4(x-7)/x(x+5)
I understand the final equation. I'd just love to know were she got that a and the x (by iself on the denominator) from! Thanks (:
Okay, conditions:
vertical asymptote: x=-5, x=0
Horizontal asymptote: y=0
x-intercept=7; f(1)=4
On the test i had no idea how to do it, but after seeing her key,I somewhat understand. I looked in the textbook and was able to see where many things came from.
a(x-7)/(x+5)(x)
for one, i have no idea where the a and the x came from. I do, however, understand that the (x-7) is from the x-int. and that the (x+5) is from the v.a.
4=a(1-7)/(1+5)(x) again, no idea where the a and x came from. I see that 4=f(1) which means that y=4 and x=1.
4=a(-6)/(6)(1)
I understand she plugged in that last x finally with a 1 and simplified everything else.
4=-a, a=-4
f(x)=-4(x-7)/x(x+5)
I understand the final equation. I'd just love to know were she got that a and the x (by iself on the denominator) from! Thanks (: