Examples
f(x)=x2+3x+4f(x)=x2+3x+4 , g(x)=x-1g(x)=x−1 , (f∘g)(f∘g)
Step 1
Set up the composite result function.
f(g(x))f(g(x))
Step 2
Evaluate f(x-1)f(x−1) by substituting in the value of gg into ff.
f(x-1)=(x-1)2+3(x-1)+4f(x−1)=(x−1)2+3(x−1)+4
Step 3
Step 3.1
Rewrite (x-1)2(x−1)2 as (x-1)(x-1)(x−1)(x−1).
f(x-1)=(x-1)(x-1)+3(x-1)+4f(x−1)=(x−1)(x−1)+3(x−1)+4
Step 3.2
Expand (x-1)(x-1)(x−1)(x−1) using the FOIL Method.
Step 3.2.1
Apply the distributive property.
f(x-1)=x(x-1)-1(x-1)+3(x-1)+4f(x−1)=x(x−1)−1(x−1)+3(x−1)+4
Step 3.2.2
Apply the distributive property.
f(x-1)=x⋅x+x⋅-1-1(x-1)+3(x-1)+4f(x−1)=x⋅x+x⋅−1−1(x−1)+3(x−1)+4
Step 3.2.3
Apply the distributive property.
f(x-1)=x⋅x+x⋅-1-1x-1⋅-1+3(x-1)+4f(x−1)=x⋅x+x⋅−1−1x−1⋅−1+3(x−1)+4
f(x-1)=x⋅x+x⋅-1-1x-1⋅-1+3(x-1)+4f(x−1)=x⋅x+x⋅−1−1x−1⋅−1+3(x−1)+4
Step 3.3
Simplify and combine like terms.
Step 3.3.1
Simplify each term.
Step 3.3.1.1
Multiply x by x.
f(x-1)=x2+x⋅-1-1x-1⋅-1+3(x-1)+4
Step 3.3.1.2
Move -1 to the left of x.
f(x-1)=x2-1⋅x-1x-1⋅-1+3(x-1)+4
Step 3.3.1.3
Rewrite -1x as -x.
f(x-1)=x2-x-1x-1⋅-1+3(x-1)+4
Step 3.3.1.4
Rewrite -1x as -x.
f(x-1)=x2-x-x-1⋅-1+3(x-1)+4
Step 3.3.1.5
Multiply -1 by -1.
f(x-1)=x2-x-x+1+3(x-1)+4
f(x-1)=x2-x-x+1+3(x-1)+4
Step 3.3.2
Subtract x from -x.
f(x-1)=x2-2x+1+3(x-1)+4
f(x-1)=x2-2x+1+3(x-1)+4
Step 3.4
Apply the distributive property.
f(x-1)=x2-2x+1+3x+3⋅-1+4
Step 3.5
Multiply 3 by -1.
f(x-1)=x2-2x+1+3x-3+4
f(x-1)=x2-2x+1+3x-3+4
Step 4
Step 4.1
Add -2x and 3x.
f(x-1)=x2+x+1-3+4
Step 4.2
Simplify by adding and subtracting.
Step 4.2.1
Subtract 3 from 1.
f(x-1)=x2+x-2+4
Step 4.2.2
Add -2 and 4.
f(x-1)=x2+x+2
f(x-1)=x2+x+2
f(x-1)=x2+x+2