Monday, May 19, 2008

Q) The quadratic equation whose roots are twice those of 3x^2+5x-2=0 is ?

A)
3x^2+5x-2 = 0
= x^2 - (sum of roots)x + (product of roots)

If roots are multiplied by two, it should become:
x^2 - 2(sum of roots)x + (2*2*product of roots)

So answer is
3x^2 + 2*5x - 2*4 = 0
=> 3x^2 + 10x - 8 = 0


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