Let f(x)=x^2f(x)=x2 and g(x)=sqrtxg(x)=x, how do you find the domain and rules of (f/g)(x)(fg)(x)?

1 Answer
Oct 26, 2017

Domain: x > 0x>0
(f/g)(x)=sqrt(x^3)" or, equivalently "x^(3/2)(fg)(x)=x3 or, equivalently x32

Explanation:

(f(x))/(g(x))=(x^2)/sqrt(x)f(x)g(x)=x2x ...and since
color(white)("XXXXXX")XXXXXXdivision by zero is undefined, and
color(white)("XXXXXX")XXXXXXsquare root of negative numbers are not defined for Real values
color(white)("XXX")XXXwe can eliminate any values of x <= 0x0
leaving us with a domain of x > 0x>0

x^2/sqrt(x)=x^2xxx^(-1/2)=x^(3/2)x2x=x2×x12=x32 or
color(white)("XXXXXXXXXX")=(sqrt(x))^3XXXXXXXXXX=(x)3 or
color(white)("XXXXXXXXXX")=sqrt(x^3)^2XXXXXXXXXX=x32