Finding even and odd function

Question

Assignment:

Determine f_e(x) and f_o(x). Is f even? Odd? Neither?

(a) x⁴ + x³ + x² + x + 1

(b) sin(sin x)

(c) cos(sin x)

f_e(x) means even function.

f_o(x) means odd function.

The problems are from Even, Odd, and Periodic Functions.

Provide complete and step by step solution for the question and show calculations and use formulas.