We will use uniform quantization to quantize a signal

$x(t)=cos(2000t)cos(800t)+cos(2500t)$

a$)$ What are the maximum and minimum values of $x(t)?$

b$)$ What is the power of $x(t)?$

c$)$ If $x(t)$ is uniformly quantized to $4$ bits, what will be mean square quantization error?