Calculate the gradient of the function y=x^2+6x when y=-9

-9=x^2+6x

0=x^2+6x+9

0=(x+3)(x+3)

when y=-9 x=3

dy/dx=2x+6

dy/dx=2(3)+6=12

HM
Answered by Hassan M. Maths tutor

5234 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

The line PQ is the diameter of a circle, where points P and Q have the coordinates (4,7) and (-8,3) respectively. Find the equation of the circle.


Write (3 + 2√5)/(7 + 3√5) in the form a + b√5


Solve $\color{orange}{a}x^2 - \color{blue}{b}x + \color{green}{c} = 0$


Find the turning points of the equation y=4x^3-9x^2+6x?


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2026 by IXL Learning