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