Question

Find the least integral value of k for which the equation x^2 -2(k+2)x + 12 + k^2 = 0 has two different real roots.
Solution

X^2-2(k+2)x+12+k^2=0
I ≥ 0
[2(k+2)]-4×(12+k^2)>0
4.(k^2+4+4k)-48-4k^2>0
16+16K-48>0
16-32>0
(k-2)>0
k>2
Least integral value = 3