Question

Functions f and g are defined by
f(x): k-x for xER, where k is a constant.
g(x): 9/(x+2) for xER, x does not = -2

Find the values of k for which the equation f(x) = g(x) has two equal roots and solve the equation f(x) = g(x) in these cases.

Answer 1

k-x=9/(x+2)
(k-x)(x+2)=9
kx+2k-x^2-2x=9
-x^2+(k-2)x+2k-9=0 ----a
a=-1 b=(k-2) c=(2k-9)
b^2-4ac=0
(k-2)^2-4(-1)(2k-9)=0
solve the above equation and find k
put it back in a and find x

Answer 2

Thanks! Very much appreciated.

Answer 3

np :)