Unit 3: Linear Functions

Key words

• SlopeKey word · Unit 3SlopeVertical change divided by horizontal change.Exactly: For a nonvertical line through distinct points $(x_1,y_1)$ and $(x_2,y_2)$, its slope is $m=\frac{y_2-y_1}{x_2-x_1}$.Mix-up alert: A vertical line has undefined slope; a horizontal line has slope zero.See this in Key wordsClose meaning
• Linear functionKey word · Unit 3Linear functionA function that changes by the same amount for each equal input step.Exactly: A function of the form $f(x)=mx+b$, with real constants $m$ and $b$.Mix-up alert: A straight vertical line is not a function of x.See this in Key wordsClose meaning
• Piecewise functionKey word · Unit 3Piecewise functionA function that uses different rules for different inputs.Exactly: A function defined by different expressions on specified parts of its domain, assigning one output to each allowed input.Mix-up alert: Choose the rule by the input, not by the output.See this in Key wordsClose meaning