Evaluating Functions with Desmos for the SAT

The video tutorial introduces a quadratic function, f(x) = 3x^2 - 7x + 80, and explains how to determine its y-intercept by examining the constant term. It then demonstrates how to evaluate the function at a specific value, such as f(7), using both manual calculation and the Desmos graphing tool. The tutorial highlights the efficiency of using Desmos for quick evaluations, emphasizing its usefulness in saving time and effort compared to manual calculations.

What is the y-intercept of the function f(x) = 3x^2 - 7x + 80?

• 3

• -7

• 0

• 80

How can you determine the y-intercept of a quadratic function?

• By setting x to 1

• By looking at the coefficient of x^2

• By looking at the coefficient of x

• By looking at the constant term

What is the value of f(7) for the function f(x) = 3x^2 - 7x + 80?

• 150

• 100

• 200

• 178

What is the first step to manually evaluate f(7) for the function f(x) = 3x^2 - 7x + 80?

• Add 80 to 7

• Subtract 7 from 7

• Square 7

• Multiply 3 by 7

What tool can be used to quickly evaluate the function f(x) at any given point?

• Graph paper

• Spreadsheet

• Calculator

• Desmos

Why is it advantageous to use Desmos for evaluating functions?

• It is faster and more efficient

• It can only be used for quadratic functions

• It requires manual calculations

• It provides step-by-step solutions