SAT Practice Math Questions: Linear and Quadratic Functions - dummies

# SAT Practice Math Questions: Linear and Quadratic Functions

Although functions seem like a pretty abstract concept, a huge number of real-life situations can be modeled using functions. To do well on the Math section of the SAT, you definitely want to know the most common types of functions: linear and quadratic.

All linear functions have the form y = mx + b or f (x) = mx + b. In graphing terms, m represents the slope of the line being drawn, while b represents its y-intercept.

Quadratic functions, on the other hand, have the form y = ax2 + bx + c or f (x) = ax2 + bx + c. Graphically, they’re represented by a parabola, a shape that resembles the basic rollercoaster hump.

The following practice questions deal with both linear and quadratic functions.

## Practice questions

1. If f (x) is a linear function with a slope of 2, passing through the point (–2, –3), f (x) must also pass through the point
• A. (1, 2)
• B. (1, 3)
• C. (2, 2)
• D. (2, 3)
2. If a2b2 = 40 and ab = 10, then a + b =
• A. 4
• B. 10
• C. 14
• D. 30