1.6 combining functions; composite functions
sum of functions
(f+g)(x)=f(x)+g(x)
difference of functions
(f-g)(x)=f(x)-g(x)
decomposing
-function can have simpler functions in several different ways by choosing various "inner" functions -H=f°g (H as composite of simpler functions f and g) 1) define g(x) as any expression in H 2) get f(x) by replacing H with f and replacing g(x) with x 3) H(x)=f(g(x))=f°g(x)
composite functions
-if f and g are two functions, the composition of function f with function g is written as (f°g)(x)=f (g(x)) -read "f of g of x" -when computing, replace every x in f(x) with g(x)
quotient of functions
f/g (x)=f(x)/g(x)
product of functions
fg(x)=f(x)•g(x)