I would like to have some help with this problem: 

U = 93 [V]

f = 600 [Hz]

L = 0,24 [H]

C = 0,16 [μF]

R = 950 [Ω]

[![enter image description here][1]][1]


This is the RCL circuit which I need to find the impedance \$Z\$ in and \$\cos(\alpha)\$

The first two questions that I had was to find the inductive reactance, XL, and the capacitive reactance, XC. I figured them out and I got XL = 905 ohm and XC = 1658 ohm. 

I thought that I would use this formula: 

$$\mathrm{impedance} \, Z = \sqrt{R^2+(X_L-X_C)^2}$$

  [1]: https://i.sstatic.net/WJ6PZ.png
  [2]: https://i.sstatic.net/yT6j4.png

But I can't get it right. 
I would also like to know if \$\cos(\alpha)\$ is solved through \$\cos(\alpha) = \frac{R}{Z}\$