Thread: Quadratic equation from given roots.

Quadratic equation from given roots.
For example if the roots were -6 and 2 how would I write quadratic equation.

Originally Posted by power2600

Quadratic equation from given roots.
For example if the roots were -6 and 2 how would I write quadratic equation.

(x-(-6))(x-2) = (x+6)(x-2) = x^2 + 4x -12 = 0

RonL

Thanks for the help

Also, while I am on the subject of quadratic equations
I have been having some trouble with Solving 2 var quadratic equations.
Example: h=-16t^2+80t+2
Solve for both t and h.

I get:
t= +-(sqrt {102-h+10})/4

Originally Posted by power2600

Thanks for the help

Also, while I am on the subject of quadratic equations
I have been having some trouble with Solving 2 var quadratic equations.
Example: h=-16t^2+80t+2
Solve for both t and h.

I get:
t= +-(sqrt {102-h+10})/4

i didn't check if you solved for t correctly, but i'll tell you this. you can't solve for 2 unknowns with one equation. you need two equations to solve 2 unknowns, and 3 to solve for 3 and so on. you can solve for one unknown in terms of the other, as you did (you solved for t in terms of h), but that's about it. unless you were given some other condition

Originally Posted by Jhevon

i didn't check if you solved for t correctly, but i'll tell you this. you can't solve for 2 unknowns with one equation. you need two equations to solve 2 unknowns, and 3 to solve for 3 and so on. you can solve for one unknown in terms of the other, as you did (you solved for t in terms of h), but that's about it. unless you were given some other condition

Not always true.

Say x,y,z>= 0

Solve for:

x^3+y^3+z^3 = xyz



Example 2:

Solve for:

x^3=y^2+1

Where x,y are positive integrers.

It turns out you CAN solve them.