Question

\[ f(x)=x^{2}+2(k+1) x+9 k-5 \] Q5. The values of \( k \) such that \( f(x) \) has real zeros is/are - (A) \( k \leq 1 \) (C) \( k \geq 1 \) (b) \( k \geq 6 \) (D) \( k \leq 6 \)

Answer 1

for roots to be real 

its discriminant must be >=0

there b²-4ac>=0

4k²+4+8k-36k+20>=0

k²-7k+6>=0

(k-6)(k-1)>=0

k=<1 and k>=6