Write a quadratic equation ( in the form ax^2+bx+c=0) whose roots are 2 and -2/3
I think I should work backwards from the roots to find the quadratic equation but am unsure how to do that.
2007-11-06 03:03:06 · 6 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
hmmmmm is this hard???
put it as
(x-r1)(x-r2)=0 then multiply
(x-2)( x+2/3) =0
(x-2)(3x+2) =0
3x^2 -4x -4=0
2007-11-06 03:09:32 · answer #1 · answered by mbdwy 5 · 0⤊ 0⤋
To form an equation from the roots, you must,
x^2 - ( sum of both root ) x + ( multiply of both roots )
so the answer is
x^2 - (4/3)x + (-4/3)
x^2 - 4/3 x - 4/3
2007-11-06 11:14:16 · answer #2 · answered by Mizuno 2 · 0⤊ 0⤋
If the roots are 2 and -2/3 just shove them in....
(x - 2) (x + 2/3)
x^2 - 2x + 2/3x - 4/3
Gives..... x^2 - 4/3 x - 4/3
2007-11-06 11:08:01 · answer #3 · answered by Doctor Q 6 · 0⤊ 0⤋
Multiply (x-2)(x+2/3)
2007-11-06 11:06:43 · answer #4 · answered by norman 7 · 1⤊ 0⤋
3x^2-4x+4=0
2007-11-06 11:06:26 · answer #5 · answered by naveen 2 · 0⤊ 0⤋
(x-2)(x+2/3) = x^2 - 4/3x - 4/3
2007-11-06 11:07:44 · answer #6 · answered by robertonereo 4 · 1⤊ 0⤋