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Another . ? :D
If alpha and beta are the roots of the equation ax^2+bx+c, then the quadratic equation, ax62-bx(x-1)+c(x-1)^2 has roots
\[\large{ax^2 - bx(x-1) + c(x-1)^2 = ax^2 - bx^2 + bx + cx^2 - 2cx + c}\] \[\large{=(a-b+c)x^2 - 2cx + c}\]
Since alpha and beta are roots of ax^2+bx+c then: \[\large{\alpha \beta = \cfrac{c}{a}}\] \[\large{\alpha + \beta = \cfrac{-b}{a}}\]
yes okay..
Now let the roots of the new equation be x1 and x2, then: \[\large{x_1 + x_2 = \cfrac{-(-2c)}{a-b+c} = \cfrac{2c}{a-b+c}}\] \[\large{x_1 x_2 = \cfrac{c}{a-b+c}}\]
yes
\[\large{\implies x_1 + x_2 = \cfrac{2(\cfrac{c}{a})}{1 - \cfrac{b}{a} + \cfrac{c}{a}}}\]
Now we know the values of c/a and b/a in terms of alpha, beta
nice got it
Thus: \[\large{x_1+x_2 = \cfrac{2\alpha\beta}{1 + \alpha + \beta + \alpha \beta}}\]
Similarly: \[\large{x_1 x_2 = \cfrac{\cfrac{c}{a}}{1- \cfrac{b}{a} + \cfrac{c}{a}}}\] \[\large{\implies x_1 x_2 = \cfrac{\alpha\beta}{1+\alpha+\beta+\alpha \beta}}\]
thanx
Your welcome :)
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