# Inverse Tangent equation

• Jun 2nd 2008, 05:45 AM
ajwillshire
Inverse Tangent equation
Hi,

Got a bit of a problem,

I have an equation of a curve

y=c*atan(d(x+e))-x

and i want to find out values of x where y equals zero.

Any ideas?

I differentiated my equation so i could find the peak if that helps anyone.

dy/dx = (c*d/(1+(d(x+e))^2))-1

Andrew
• Jun 2nd 2008, 05:52 AM
topsquark
Quote:

Originally Posted by ajwillshire
Hi,

Got a bit of a problem,

I have an equation of a curve

y=c*atan(d(x+e))-x

and i want to find out values of x where y equals zero.

Any ideas?

I differentiated my equation so i could find the peak if that helps anyone.

dy/dx = (c*d/(1+(d(x+e))^2))-1

Solving $0 = c~tan^{-1}(dx + e) - x$ for x has nothing to do with the derivative (unless you are trying something like Newton's method to approximate it.) This equation cannot be solved exactly as it stands. (There may be some specific values of c, d, and e such that it can be, but I can't think of any at the moment.)