$f(x)=x^3+p x^2+q x+10$ has a maximum at x = -3 and a minimum at x = 1. The values of p and q are:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → $p = 3, q = -9$
$f(x)=x^3+p x^2+q x+10$
It has maximum at $x=-3$ and a minimum at $x=1$
To find critical points,
$f'(x)=0$
$⇒3x^2+2px+q=0$
and, $f'(-3)=0$
$⇒3(-3)^2+2p(-3)+q=0$
$⇒6p-q=27$ ...(1)
$f'(1)=0$
$⇒3(1)+2p+q=0$
$⇒2p+q=-3$ ...(2)
Solving both (1) and (2), we get
$p=3$ and $q=-9$