1. The problem statement, all variables and given/known data A conical pendulum with an unelastic tether has a mass of 4.25 kg attached to it. The tether is 2.78 m. The mass travels around the center every 3.22 seconds. What angle does the rope make in relation to its original position? m=4.25 kg T=3.22 s L=2.78 m 2. Relevant equations FTx=4(pi^2)R/T^2m FTy=mg R=Lcos(phi) 3. The attempt at a solution To find the angle, I decided to use equations for force tension, then set the equations equal to each other using trigonometric functions, cosine on the equation for FTy and sine on the equation for FTx. The cosine on FTy canceled out with the cosine on the inserted equation for R, as well as the mass on both sides, leaving me with 4(pi^2)Lcos(phi)/T^2 on one side of the equation, and g on the other. However, I seem to have hit a snag. I cannot use inverse trig functions, as I do not have phi yet. I either messed up the symbolics, or something else is amiss.