Question

If one of the zeroes of the quadratic polynomial (k-1)x2+kx+1 is -3, then find the value of k.

Answer 1

Let p(x) = (k-1)x^2 + kx + 1

Since it is given that -3is one of the zeroes of p(x), thus p(-3) must be equal to zero.

Hence,

p(-3) = 0

=> (k-1)(-3)^2 + k(-3) + 1 = 0

=> 9k - 9 - 3k + 1 = 0

=> 6k - 8 = 0

=> k = 8/6

=> k = 4/3