f(x) = 2x-3
g(x) = x^2
-2
We need to find fog(x) and
gof(x).
We know that fog(x) =
f(g(x))
Then we will substitute with g(x) = x^2
-2
==> fog(x) = f( x^2 -2)
Now
we will substitute with x = x^2-x in f(x).
==> fog(x) =
2(x^2-2) -3
We will open
brackets.
==> fog(x) = 2x^2 -4
-3
==> fog(x) = 2x^2 -7
gof(x) =
g(f(x)) = g(2x-3) = (2x-3)^2 -2 = 4x^2 -12x + 9 -2 = 4x^2 -12x
+7
==> fog(x) = 2x^2 -7
==> gof(x) = 4x^2 -12x +
7
No comments:
Post a Comment