‹ Back to the paper
Choose the correct option.
If f(x) = kx² + 7x - 4 and f'(5) = 97 then what is the value of k? (Understanding)
If $f(x) = kx^2 + 7x - 4$ and $f'(5) = 97$ then what is the value of $k$? (Understanding)
- (a)$-4$
- (b)$0$
- (c)$4$
- (d)$9$
Answer
Answer
Official answer keyCorrect option: (d)
Answer: (d) $9$
$f'(x) = 2kx + 7$, so $f'(5) = 10k + 7 = 97$, giving $k = 9$.