Can you help with this question?
i) Use calculus to find in the form kx + ly = n, where k,l and n are whole numbers, the equation of the normal to the curve at x=-1
ii) Find the point on the curve such that the equation of the normal is 20y+4x=51
Hope you can help
for i) rearrange to make y the subject, find dy/dx, then rmb the normal gradient is -1/m
Thanks
and what about ii)?
Was there an equation for the curve given with this question, or am I missing something?
From a quick read I think you should do the following:
- Rearrange so you have y in terms of x
- Get the gradient of that equation, we'll call that "m"
- So the derivative of the curve will = -1/m, at the point of intersection (the place the normal occurs)
- Make the derivative of the curve = -1/m, this will give you x coordinate
- put x coordinate back into either equation to give y coordinate