Given that f(x) = −x + 4 and g(x) = −2x − 3, solve for f(g(x)) when x = 2.
f(g(x)) is a "composite function." Can you define what that means? Once you understand this concept, the actual algebra and arithmetic are relatively simple.
I don't really remember but know it
Could you possibly look it up? And then write it down, for later reference and practice?
yes
So, what have you learned by looking up "composite function" ?
x is a placeholder and there's domain and range.
I see that g(x) is the INPUT to function f(x), in f(g(x)). Write out f(x). Replace every instance of x with empty parentheses: f( ) = -( ) + 4 Write function g(x) = -2x -3 inside those empty parentheses: g(x) in the left set of empty parentheses, -2x-3 in the right set. Simplify the resulting expression.
f(x)=-2(3)+4
f( ) = -( ) + 4 has 2 sets of empty parentheses. Write g(x) inside the left set and write -2x-3 inside the other set. This will give you an expression for the composite function f(g(x)). Simplify the right side.
Join our real-time social learning platform and learn together with your friends!