3.11. Suppose we are given the following information about a signal x[n]: 1. x[n] is a real and even signal. 2. x[n] has period N = 10 and Fourier coefficients

ak. 3. a11 = 5. \text { 4. } \frac{1}{10} \sum_{n=0}^{9}|x[n]|^{2}=50 Show that x[n] = A cos(Bn + C), and specify numerical values for the constants A,B, and C.