- #1
Porty
- 7
- 0
This is probably very easy, but anyway..
I just don't really understand the question, therefore don't know what answer to give..
The question reads...
For what values of [tex]n[/tex] will one root of the equation
[tex] (n - 2)x^2 + (n + 2)x + 2n + 1 = 0 [/tex] be the reciprocal of the other?
I know the answer is [tex]n = -3 [/tex]
if [tex]\alpha[/tex] and [tex]\beta[/tex] are the roots of [tex]ax^2 + bx + c = 0,[/tex]
then [tex] \alpha + \beta = -\frac{b}{a}[/tex] and [tex] \alpha\beta = \frac{c}{a}[/tex]
I do
[tex]\alpha + \beta = - \frac{(n+2)}{(n-2)}[/tex]
then solve for [tex]n[/tex] which gives me [tex]n=2[/tex]
and
[tex]\alpha\beta = \frac{(2n+1)}{(n-2)}[/tex]
then solve for [tex]n[/tex] which gives me [tex]n=-3[/tex]
I need to know how the [tex]n=-3[/tex] relates to the answer..??
I just don't really understand the question, therefore don't know what answer to give..
Homework Statement
The question reads...
For what values of [tex]n[/tex] will one root of the equation
[tex] (n - 2)x^2 + (n + 2)x + 2n + 1 = 0 [/tex] be the reciprocal of the other?
I know the answer is [tex]n = -3 [/tex]
Homework Equations
if [tex]\alpha[/tex] and [tex]\beta[/tex] are the roots of [tex]ax^2 + bx + c = 0,[/tex]
then [tex] \alpha + \beta = -\frac{b}{a}[/tex] and [tex] \alpha\beta = \frac{c}{a}[/tex]
The Attempt at a Solution
I do
[tex]\alpha + \beta = - \frac{(n+2)}{(n-2)}[/tex]
then solve for [tex]n[/tex] which gives me [tex]n=2[/tex]
and
[tex]\alpha\beta = \frac{(2n+1)}{(n-2)}[/tex]
then solve for [tex]n[/tex] which gives me [tex]n=-3[/tex]
I need to know how the [tex]n=-3[/tex] relates to the answer..??