If function f(x) satisfies f(x) = f(x + T), say f(x) is a periodic function with period T. In HW#1, we learned the characteristic equation of symmetric function: f(x) = f(2c - x), which means function f(x) is symmetric about x = c. Today, let's think about another interesting case. Assume h(x) is symmetric on both x = a and x = b (assume b> a > 0). (a) Show h(x) is a periodic function. (6 points) (b) How many symmetric axis does h(x) have? (include both x = a and x = b) (4 points)