Susie is telling Tim about linear functions. Check all choices that accurately finish her sentence.

Question

"In order to be a linear function, a graph must..."

... be a curve.

... be a line.

... have positive slope.

... have negative slope.

... have inputs and outputs.

... pass the vertical line test.

Answer 1

The accurate choices that finish Susie's sentence are:

• ... be a line.
• ... have inputs and outputs.
• ... pass the vertical line test.

To clarify:

• A linear function is represented by a straight line, not a curve.
• A linear function can have either positive or negative slope, but it does not have to have a specific sign (positive or negative).
• The inputs and outputs are essential characteristics of functions in general, including linear functions.
• The vertical line test is a method to determine if a graph represents a function, which applies to linear functions as well.