The slope of the tangent to the curve y = 3x2 + 2kx - 5 at x = 1 is 9. The value of k is:
Answer & explanation
Correct answer: option 4
$y = 3x^2+2kx-5⇒\frac{dy}{dx}=6x+2k$
∴ Slope of tangent at x = 1 is 9
$6(1)+2k=9$
$6+2k=9⇒2k=9-6⇒2k=3$
$k=\frac{3}{2}$