Find the value of k for real and equal roots`.(k+1)x^2-2(k-1)x+1=0`

Options

A. `k=0 only`
B. `k=-3 only`
C. `k=0 or k = 3`
D. `k=0 or k = - 3`

Answer

C

Explanation

As given :
roots of the quadratic equation
` (k+1)x^(2) - 2(k-1) x+1 = 0 ` are equal ,
Its discriminant
` { -2 (k-1)}^(2)-4 (k+1)=0`
` rArr 4 (k^(2) - 2k+1) - 4 (k+1) = 0 `
` rArr k^(2) - 2k + 1 - k-1 =0`
`k^(2)-3k=0 " "rArr k=0, k=3`.