What is the answer to this?

What are the domain and range of f(x)=[1/5]x

Write a polynomial function f of least degree that has rational coefficients, a leading coefficient of 1, and the given zeros. 3, 4+2i, 1+(sqrt)7 the answer is supposed to be: f(x)=x(^5)-13x(^4)+60x(^3)-82x(^2)-144x+360 what am i doing wrong?

Write the sine and cosine values of a, b, respectively, in the figure for (1) and (2) + explanation.