A known input and a function rule signal function evaluation: put the input wherever the variable appears to find the output. In Desmos, define the function, then type its name with the given input. For a negative input, use parentheses so the square applies to the whole number, not only to its positive part.
Hints
- Hint 1
The number you put into a function is its input. Here, the input is negative. What expression do you get when you replace in the rule with ?
- Hint 2
An exponent tells you what to multiply before using the or subtracting . Keep the whole input in parentheses: means . What number is that?
Step-by-step
Evaluate the function in Desmos
Step 1Put the input into the rule
A function takes an input and gives back an output. Since the input is , means replace with : . Type in Desmos to save the rule for evaluation.
- Step 2
Read the output
Type on the next line. Desmos shows . Square the whole negative input: ; the rule then multiplies by and subtracts . So the function’s output when is . Choice C.