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OpenStudy (anonymous):
If \[a \neq b \] but \[a ^{2} = 5a - 3 \] and \[b ^{2} = 5b - 3 \]
then find the equation whose roots are
\[\frac{ a }{ b } and \frac{ b }{ a }\]
OpenStudy (anonymous):
@ganeshie8
OpenStudy (vishweshshrimali5):
See:
a quadratic equation with roots \(\alpha\) and \(\beta\) is given by :
\[ax^2 + bx + c = 0\]
iff
\[\alpha + \beta = \cfrac{-b}{a}\]
\[\alpha \beta = \cfrac{c}{a}\]
OpenStudy (anonymous):
Yes i know that
OpenStudy (vishweshshrimali5):
Gud now here replace alpha and beta by a/b and b/a
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OpenStudy (vishweshshrimali5):
Nope
OpenStudy (vishweshshrimali5):
See:
\[ax^2 + bx + c = 0\]
\[\implies x^2 + \cfrac{b}{a} x + \cfrac{c}{a} = 0\]
\[\implies x^2 - \text{(sum of roots)} x + \text{(product of roots)} = 0\]
OpenStudy (anonymous):
But the roots are
\[\frac{ a }{ b } and \frac{ b }{a }\]
OpenStudy (vishweshshrimali5):
Here sum of roots will be:
\[\cfrac{a}{b} + \cfrac{b}{a} = \cfrac{a^2 + b^2}{ab}\]
product of roots will be :
\[\cfrac{a}{b} \cfrac{b}{a} = 1\]
OpenStudy (vishweshshrimali5):
Did you get it upto this step ?
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OpenStudy (anonymous):
(a+b)^2 -2ab / ab
OpenStudy (vishweshshrimali5):
Yes
OpenStudy (anonymous):
This is the sum of roots
sum of roots is :- -b/a
Product of roots is :- c/a
Substituting that gives what i just wrote
OpenStudy (vishweshshrimali5):
no why are you including this c
OpenStudy (anonymous):
which "c"
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