The entire graph of the equation `y=x^2+k x-x+9`in strictly above the `x-a xi s`if and only if`k

The entire graph of the equation `y=x^2+k x-x+9`in strictly above the

1.	The entire graph of the equation `y=x^2+k x-x+9`in strictly above the `x-a xi s`if and only if`k
Answer» `y=x^(2) + (k-1)x+9= (x+ (k-1)/(2))^(2) + 9 - ((k-1)/(2))^(2)` For the entire graph to be above the x-axis, we should have `" "9- ((k-1)/(2))^(2) gt 0` `rArr" "k^(2)-2k -35 lt 0 rArr (k=7)(k+5) lt 0` `rArr -5 lt k lt 7`