it is asking to plot the point (3, f(3))

Question

This is a function of x and is asking to plot this point but I am confused.

Answer 1

They want you to plot the point (x, y) where x = 3 and y = f(3). f(3) is the value of f(x) when x = 3.  For example, if

f(x) = 2x² + x - 4 then f(3) = 2(3²) + 3 - 4 = 17 and the point to be plotted is (3, 17).