
Howard J. answered 09/22/19
Principal Mechanical Engineer with >30 years' math coaching experience
f(x)=x^2
g(x)=x^3
f(x)=√x
g(x)=∛x
For a function h(x), if h(-x)=h(x), then h(x) is even. If h(-x)=-h(x), then h(x) is odd.
First one f(x)=x2
f(-x)=(-x)2=x2=f(x) so the function is even.
Second one g(x)=x^3
g(-x)=(-x)3=-x3=-g(x) so the function is odd.
Third one f(x)=√x
f(-x)= √(-x). The function is undefined for x>0. For x<0, the function is defined but f(-x)≠f(x). For example, if x=-4, f(--4)= √--4=√4=±2. The function is neither.
Fourth one g(x)=∛x
g(-x)=∛(-x)=-∛x=-g(x) so the function is odd.