Remember that the solutions have to be approximated to the nearest hundredth. This is two decimal places.
C
Practice makes perfect
The given quadratic equation is already written in standard form. Therefore, we can enter this equation 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.
Because of the sign changes, the solutions are somewhere between x= - 1 and x= 0, and between x= 4 and x= 5. To find these exact values, we need to see smaller increments in the table. To change the table settings, push 2ND and then WINDOW. Then change TblStart to -1 and â–³ Tbl to 0.1.
Next, push 2ND and GRAPH to see the table again with the new setup.
Now we can see that the smaller solution is between x=-0.7 and x=-0.6. To find this exact value, we need to see even smaller increments in the table. Again, to change the table settings, push 2ND and then WINDOW. Then change TblStart to -0.66 and â–³ Tbl to 0.01.
Next, push 2ND and GRAPH to see the table again with the new setup.
Finally, we can see that x=-0.61 provides a value of 0 in the y-column.
Similarly to the previous interval, we can find the solution between x= 4 and x= 5. We need to see smaller increments in the table. To change the table settings, push 2ND and then WINDOW. Then change TblStart to 4 and â–³ Tbl to 0.1.
Next, push 2ND and GRAPH to see the table again with the new setup.
Now we can see that the solution is between x=4.1 and x=4.2. To find the exact value, we need to see even smaller increments in the table. To change the table settings, push 2ND and then WINDOW. Then change TblStart to 4.1 and â–³ Tbl to 0.01.
Next, push 2ND and GRAPH to see the table again with the new setup.
Finally, we can see that x=4.11 provides a value of 0 in the y-column. We can state that the solutions to the quadratic equation are x=-0.61 and x=4.11. This result corresponds to answer C.
