Question

If the root of X3+ kx + K+ 3 is equal to zero are real and equal what is the value of k​

Answer 1

The roots are real and equal then the discriminant must be zero

So b²-4ac = 0

=>K²-4(1)(k+3)= 0

=> K²-4k-12 = 0

=> K2-6k+2k-12 = 0

=>K(K-6)+2(k-6)= 0

=>(K-6)(k+2) = 0

K = 6 or -2