Question 211·Easy·Nonlinear Functions
The function is defined by . What is the value of ?
For function-evaluation questions, immediately rewrite the expression with the given input in place of , then simplify using strict order of operations: exponents first, then multiplication, then addition/subtraction. Pay close attention to negative signs around squared terms like by squaring the variable first and then multiplying by the coefficient, which helps avoid common sign errors and lets you reach the answer quickly.
Hints
Focus on what g(2) asks you to do
You are not solving an equation here. You are evaluating the function at . Think: where do you see in the formula, and what should you replace it with?
Apply the order of operations
After you substitute into , make sure to do exponents first, then multiplication, then addition.
Handle the negative with the square carefully
When you evaluate at , square the 2 first to get , then multiply by . Do not square the .
Desmos Guide
Evaluate the function at x = 2
In a Desmos expression line, type -3*(2)^2 + 12*(2) + 5 and press Enter. The value that Desmos outputs is the value of .
Step-by-step Explanation
Understand what g(2) means
The notation means: take the formula for and replace every with , then simplify.
Substitute x = 2 into the function
Start with the function:
Now substitute :
Next, handle the exponent first.
Evaluate the exponent and multiply
Compute and then multiply:
- So
- And
Now becomes:
Add the terms to find g(2)
Combine the numbers step by step:
So , which corresponds to choice C.