Summary: Review

Key Concepts

Formulas for specific types of applications containing more than one variable may be solved for an unknown variable by substituting known values and solving the formula for the unknown variable.
Functions containing radicals may be graphed by substituting input values and solving for the coordinating output value to create a graph of points existing on the graph. After plotting enough points to obtain the shape of the graph, draw a smooth curve between them.
Work [latex]W[/latex], rate [latex]r[/latex], and time [latex]t[/latex] may be related by the formulas [latex]W=rt,\text{ }t=\dfrac{W}{r}\text{, and }r=\dfrac{W}{t}[/latex]
Proportions, equations of the form [latex]\dfrac{a}{b}=\dfrac{c}{d}[/latex], are helpful for setting up relationships in applications. Solve by cross-multiplying or by multiplying both sides of the equation by the reciprocal of one.

proportion: a statement of the equality of two ratios
radical formula: an equation used in certain applications that contains at least one radical expression (a variable expression using a radical such as a square or cube root)
rational formula: an equation used in certain applications that contains at least one rational expression (a variable expression in fraction form)