Q. If $x^{2} + 2x + n > 10$ for all real numbers $x$, then which of the following conditions is true?
A) $n < 11$
B) $n = 10$
C) $n = 11$
D) $n > 11$
Explanation
(d)
As we know, if $ax + bx + c > 0$, then $a > 0$ and $D < 0$
$\therefore\ \ \ (2)^{2} - 4(n - 10) < 0\ \ \ \Rightarrow \ \ \ n > 11$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.