# Math Help - Inverse Tangent equation

1. ## 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

Thanks in advance,

Andrew

2. 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

Thanks in advance,

Andrew
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.)

-Dan