Thread: need help fotr math

Originally Posted by Bajan

Hey guys, having trouble with this problem :-/

how to find a quadratic equation is standard from whoes rooot are given by

r₁=3+√2 and r₂=3-[FONT='Arial','sans-serif']√2
[/FONT]

Originally Posted by tejashtaj

how to find a quadratic equation is standard from whoes rooot are given by

r₁=3+√2 and r₂=3-[FONT='Arial','sans-serif']√2[/font]

You know the values of the two roots, and we know that one form of the quadratic for this will be given by


Thus


The simplest way to expand this (in my opinion) is to write this as

which is in the form of ,




as you can check.

-Dan

write a quadratic of the form f(x)=a[FONT='Arial','sans-serif']x² +bx +c for the quadratic function whose graph passes through the point (o,8),(8,0) and (-2,5).[/FONT]

[FONT='Arial','sans-serif'](Hint find the values of a,b and c!)[/FONT]

Originally Posted by tejashtaj

write a quadratic of the form f(x)=a[FONT='Arial','sans-serif']x² +bx +c for the quadratic function whose graph passes through the point (o,8),(8,0) and (-2,5).[/font]

[FONT='Arial','sans-serif'](Hint find the values of a,b and c!)[/font]

Substitute the given values into the general equation, and you will end up with a system of linear equations in :



and you get the following system:



Now solve for the needed coefficients.