Question

for what the value of k the quadratic equation X square - kx + 4 is equal to zero has equal roots

Answer 1

For equal roots,

Discriminent = 0

=> b^2 - 4ac = 0

=> k^2 - 4(1)(4) = 0

=> k^2 - 16 = 0

=> k^2 - 4^2 = 0

=> (k+4)(k-4) = 0

Required values of k are 4 and - 4

Answer 2

this is the method of doing this question