y= (2x-2x^2)^(1/2)

Hyperbola?

And also-- in a Taylor series approximation, when the questions asks you to use up to the fifth term (NOT the fifth power term), does that just mean the first five numbers in the series?

for example, if the series was 1 + x + x^2 + x^3 + x^4 + x^5 etc. etc., would you plug in x from the first number (1) until the fourth one (x^4) ? Or would you start with x and then go to x^5?