In a function evaluation, the number in parentheses is the input, and the rule gives the output. Replace every with the whole input, then apply exponents before multiplication and subtraction. In Desmos, define the function and enter the requested value on the next line. Without parentheses around a negative input, its square can have the wrong sign.
Hints
- Hint 1
The input is the number inside a function’s parentheses. Replace with the entire negative number. Why should you wrap that number in parentheses before squaring it?
- Hint 2
A square multiplies a number by itself, so a negative number squared is positive. Apply the exponent before multiplying by , and keep the subtraction at the end of the rule.
Step-by-step
Substitute, then evaluate in Desmos
Step 1Put the negative input into the rule
means put in for . Substitute the whole negative input, using parentheses:
The parentheses make , not just , the number being squared.
- Step 2
Evaluate the function in Desmos
Type on one line and on the next. Desmos shows . That's the output for input ; it includes the subtraction of after squaring and multiplying. The value of is . Choice A.