00:03
Writing a quadratic equation, the quadratic equation would be in the form of a x squared plus bx plus c using our roots.
00:13
Well, in finding our roots, we had our factored form of our quadratic, and our factored form would be x plus, or i should, i just didn't let me read that.
00:37
It's going to be x minus our root is equal to zero which is how we got one of our roots our second root was again our factored form x minus our second root and if we had third root that would be our polynomial again equal to zero and where the quadratic part of it comes is we would take x minus r1 and we'd multiply by x minus our second root.
01:40
And then we could use our foil to find our quadratic equations.
01:46
So if we had roots of six and four, okay, that would give me x minus six times x minus four.
01:55
And so if we used our foil, that would be x squared minus 4x minus 6.
02:06
X plus 24 combine our like terms we would get x squared minus 10 x plus 24 now we have another way to easily find the quadratic equation given our roots as well and this method actually is a little bit faster we start with x squared because we always have our quadratic x squared and then we're going to subtract the sum of the roots times x and then we're going to add the product of the roots...