A function is a rule in which, for every input it produces a single output.
Here the function is f(x) = 2x. For every input value x, the output value is doubled.
is the set of x values whereas Range
is the set of y values.
It is also called as one-one function. For two different input values a and b there there should be unique output values that is f(a) ≠ f(b).
It is also called as onto function. For every element in the codomain or range there is an x in the domain.
1) Find the inverse of the function y = x/4 - 6
y = x/4 - 6
4 y = 4 (x/4 – 6 )
4y = x – 24
x = 4y + 24
f^(-1)(x) = 4x + 24
2) If f(x) = -4x and g(x) = -x + 8, find (f . g) (3)
(f . g) (3) = f [g(3)]
g(3) = - 3 + 8 = 5
f [g(3)] = f 
= -4 (5) = -20