Having rewritten the equation in standard form, we can enter it in the calculator by pushing Y= and typing it in the first row.
Next, by pushing 2ND and GRAPH, we get a table of values for whole number inputs of x. We are looking for x-values that make the y-column equal 0.
From the table, we can see that the y-values change signs from positive to negative. Thus, y must reach 0 when x is somewhere between - 2 and - 1. To find the exact value, we will need to view smaller increments in the table. To change the table settings, push 2ND and WINDOW. Then change the TblStart to - 2 and △ Tbl to 0.01.
Now push 2ND and GRAPH to see the table again with the new configurations.
As we can see, 0 is still not showing in the y-column. However, now we can estimate the x-value more accurately. Notice that 0.0789 and - 0.0176 are the closest to 0. Since - 0.0176 is closer, we can estimate the first solution of our equation to be - 1.32.
x≈- 1.32
To find the second solution return to the original display and identify the other change in sign of y-values. Then, follow the same process as before.
We can estimate the second solution to be 8.32.
x≈ 8.32
