Skip to content
Functions and Notation
Lesson 8
0% complete

Lesson 8: Function Evaluation

Interpret function notation as substitution.

Function notation means a rule. Evaluate by replacing the variable with the given input and simplifying in order.

Key formula

f(x)=ax+b⇒f(k)=ak+bf(x)=ax+b\Rightarrow f(k)=ak+b

Worked example

f(x)=2x+10,  f(−5)=0f(x)=2x+10,\;f(-5)=0

Checkpoint

If f(x)=−2x−3, find f(−2)\text{If }f(x)=-2x-3\text{, find }f(-2)

Recap

  • - f(x) names an output rule.
  • - Parentheses in f(k) indicate input, not multiplication.
  • - Use substitution carefully to avoid sign errors.
Previous lessonOpen worked examplesExamplesPracticeTry in calculator

Track progress: 0/8 completed.