6. Find the value of p, for which one root of the quadratic equation p

1.	6. Find the value of p, for which one root of the quadratic equation px2-14x + 8 = 0 is6 times the other. (CBSE 2017-2M)
Answer» For equation px^2 - 14x + 8 = 0Let a and b are roots Given,a = 6b Sum of roots = - (-14)/pa + b = 14/p6b + b = 14/p7b = 14/pb = 2/p.............. (1) Product of roots = 8/pab = 8/p6bb = 8/p6b^2 = 8/p6(2/p)^2 = 8/pp^2/64 = p/8p^2 = 3pp^2 - 3p = 0p(p - 3) = 0p = 0 or p = 3

6. Find the value of p, for which one root of the quadratic equation px2-14x + 8 = 0 is6 times the other. (CBSE 2017-2M)

Answer»

For equation px^2 - 14x + 8 = 0Let a and b are roots

Given,a = 6b

Sum of roots = - (-14)/pa + b = 14/p6b + b = 14/p7b = 14/pb = 2/p.............. (1)

Product of roots = 8/pa*b = 8/p6b*b = 8/p6b^2 = 8/p6*(2/p)^2 = 8/pp^2/6*4 = p/8p^2 = 3pp^2 - 3p = 0p(p - 3) = 0p = 0 or p = 3