To determine the functions f and g, we must find out the
unknown coefficients a and b.
We know that the coordinates
of the intercepting point verify the expressions of the
functions.
(2,3) belongs to f(x)'s graph if and only
if;
f(2) = 3
f(2) = (a-1)*2 -
2
Removing the brackets, we'll
get:
2a - 4 = 3 => 2a = 7 => a =
7/2
(2,3) belongs to g(x)'s graph if and only
if:
g(2) = 3
g(2)=(a+1)*2 + b
+ 1
2a + 2 + b + 1 = 3, but a =
7/2
7 + b =0 => b =
-7
The function f(x) is determined and it's expression
is:
f(x) = (7/2 - 1)*x -
2
f(x) = 5x/2 - 2
The function
g(x) is determined and it's expression is:
g(x) = (7/2 +
1)x - 7 + 1
g(x) = 9x/2 -
6
The requested functions are: f(x) = 5x/2 -
2 and g(x) = 9x/2 - 6
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