Function addition, subtraction, multiplication, division (mind the denominator).
(f+g)(x) = f(x)+g(x)
Add the functions' expressions to form a sum function f+g and then evaluate input x
OR input x to each function and then add the outputs.
Example: f(x)=2x2+x-√(3x2) g(x)=-4x+2
f(2)=6.535898 g(2)=-6 f(2)+g(2)=0.535989
(f+g)(x)=2x2-3x-√(3x2)+2 (f+g)(2)=0.535989
Ex. f(x)=sin x + 1 g(x)=1/2 x (f+g)(x)=sin x + 1/2 x + 1
Ex. P(x) = R(x) - C(x) profit is revenue minus cost
Domain of the sum (f+g)(x) function (or difference function (f-g)(x), product function (fg)(x), quotient function (f/g)(x)) is the intersection of the domains of f and g. [quotient function has the additional restriction of excluding any value that makes g(x)=0]
Ex. tan(x) = sin(x) / cos(x)