A function is a rule that turns an input into an output. If a question asks for , the input is : put it wherever appears in the rule. You can define the function in Desmos and then evaluate it. Don’t stop after multiplying; the subtraction is part of the rule too.
Hints
- Hint 1
In , the number inside the parentheses is the input. Which number should replace in the rule for ?
- Hint 2
After replacing , keep both operations from the rule: multiply by , then subtract . Desmos can evaluate the function if you type its definition first.
Step-by-step
Substitute, then evaluate in Desmos
Step 1Put the input into the rule
means the function’s input is , so replace with in the given rule: . The number inside the parentheses replaces . The stays because it’s part of the rule.
- Step 2
Evaluate the function
Type in Desmos to define , then type on the next line. Desmos shows . That’s the output when the input is , so . Grid in 14.