Question 58042
find (a)f o g (b)g o f .find the domain of each function and each composite funcition.
Given: f(x)= x^2 +1 g(x)=square
 root of x

i can find f(g) and g(f) but i cant find the domains
OK....DOMAIN I SHALL TELL YOU..
THE VALUES X CAN TAKE TO MAKE THE FUNCTION REAL IS DOMAIN.
IN THE FIRST CASE 
F(X)=X^2+1....X CAN TAKE ANY REAL VALUE..SO DOMAIN IS ALL REAL NUMBERS.
IN SET NOTATION WE WRITE IT AS (-INFINITY,+INFINITY)
IN THE SECOND CASE 
G(X)=SQRT(X)
NOW IF X IS NEGATIVE THE FUNCTION BECOMES IMAGINARY..HENCE X CANNOT BE NEGATIVE.
SO WE SAY DOMAIN OF X IS ALLREAL VALUES GREATER THAN OR EQUAL TO ZERO.
IN SET NOTATION WE WRITE IT AS (0,INFINITY)