Question

If g(x)>0 for all real values of x, which of the following could be the function g?

a) g(x) = x + 1
b) g(x) = x - 1
c) g(x) = x^2 + 1
d) g(x) = x^2 - 1
e) g(x)= x^3 1

Answer 1

x^2 is the only one that is always positive but x^2-1 could be negative so you only have one choice left.