Posted by Erin on .
Solving quadratic equations by graphing?
3. x24x + 6 = 0
4. x24x1=0
5. 4x212x + 3 = 0
6. x22x4=0

Math 
MathMate,
You'll need a graphics calculator, and have the calculator plot those graphs.
The solutions are where the curve intersects the xaxis. 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.