Hi In the article: "Beam to String Transition of Vibrating Carbon Nanotubes Under Axial Tension" I have found an equation that describes the resonance frequency of a beam under axial tension. However, I have some problem solving it. The equation looks like this: x + y*Sinh[y + Sqrt[y^2 + x^2]]^0.5*Sin[-y + Sqrt[y^2 + x^2]]^0.5 - x*Cosh[y + Sqrt[y^2 + x^2]]^0.5*Cos[-y + Sqrt[y^2 + x^2]]^0.5 = 0 x is the dimensionless natural frequency and y is the dimensionless natural frequency parameter. I want to find the x for different y. I have tried to solve this equation i Mathematica but without much success. Can anyone help me?