posted by Erin on .
Solving quadratic equations by graphing?
3. x2-4x + 6 = 0
5. 4x2-12x + 3 = 0
You'll need a graphics calculator, and have the calculator plot those graphs.
The solutions are where the curve intersects the x-axis. You can refine the accuracy by zooming onto the intersection.
All of the above problems have two real solutions each, except for #3, which has no real zeroes (i.e. the roots are complex).
You are free to post your answers for a check if you wish. You can also check by solving them analytically using the quadratic equation.
If you do not have a graphics calculator, you can graph by paper and pencil with the same results.