Learning Outcomes
- Solve equations and inequalities using graphs of functions.
Example Solving Equations and Inequalities using Given Graphs
Solve the equations and inequalities using the given graphs.
- Sove the equation [latex]f(x)=g(x)[/latex].
Show Answer
[latex]f(x)=g(x)[/latex] means that their [latex]y[/latex] values are equal. So, we need to find the intersecting points of those two functions. From the graphs, we can find that [latex]f(x)[/latex] and [latex]g(x)[/latex] are intersecting at [latex](-3, 1)[/latex] and [latex](5, 5)[/latex]. Therefore, the solutions of the equation [latex]f(x)=g(x)[/latex] are [latex]x=-3, 5[/latex].
- Solve the inequality [latex]f(x) \geq h(x)[/latex].
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[latex]f(x) \geq h(x)[/latex] means that the graph of [latex]f(x)[/latex] is above or intersecting the graph of [latex]h(x)[/latex]. From the graphs, we can find the graph of [latex]f(x)[/latex] is above the graph of [latex]h(x)[/latex] when [latex]x>-7[/latex] and is intersecting the graph of [latex]h(x)[/latex] when [latex]x=-7[/latex]. So, the solution of the inequality [latex]f(x) \geq h(x)[/latex] is [latex][-7, \infty)[/latex] or [latex]\{x|x \geq -7\}[/latex].
- Solve the inequality [latex]g(x)Show Answer
[latex]g(x)
Try It
Solve the equations and inequalities using the given graphs.
- Sove the equation [latex]f(x)=g(x)[/latex].
Show Answer
Since [latex]f(x)[/latex] and [latex]g(x)[/latex] are intersecting at [latex](-3, 3)[/latex] and [latex](3, 3)[/latex], the solutions of the equation [latex]f(x)=g(x)[/latex] are [latex]x=-3, 3[/latex].
- Solve the inequality [latex]f(x) < g(x)[/latex].
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Since the graph of [latex]g(x)[/latex] is below the graph of [latex]g(x)[/latex] when [latex]x<-3[/latex] or [latex]x>3[/latex], the solution of the inequality [latex]f(x)
3\}[/latex].
- Solve the inequality [latex]g(x) \leq h(x)[/latex].
Show Answer
Since the graph of [latex]g(x)[/latex] is below the graph of [latex]h(x)[/latex] when [latex]-1
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- Solving Equations and Inequalities Using Graphs of Functions. Authored by: Michelle Eunhee Chung. Provided by: Georgia State University. License: CC BY: Attribution