To solve the equation by graphing, set the left-hand side and right-hand side of the equation as separate functions. Then enter them into the calculator.
- 2, 1, and 5
Practice makes perfect
To solve the equation by graphing we will write the equation's right-hand and left-hand sides as two separate functions.
y=x^3-4x^2-7x and y=- 10
Let's enter the above functions into the calculator by pushing Y= and typing them in the two first rows.
By pushing GRAPH, the calculator will draw the equations. For this function to be visible on the screen, we have to re-size the standard window by pushing the WINDOW button. We will change the settings to a more appropriate size and then push GRAPH.
Notice that one of the equations is a horizontal line along y=- 10. We see that the graphs intersect three times, so there are three solutions to this equation. We can find them by pressing 2ND and then CALC.
Next, to isolate which intersection we want to calculate, we have to provide some guesses as to where the intersections occur. To make sure the calculator picks the intersection point we want to find, we must make our guesses as close to it as possible. We will repeat this procedure for all three solutions.
