See functions

In a function, every input value of x outputs a single value for y

Every function has a domain (all valid real number arguments (x values)) and a range (all valid real number outputs (or y value))

To find the domain test the function for x > 0, x === 0 and x < 0. Look out for sqt(), log(), and fractions over x

To find the range, plug in values from the domain and look for patterns

You can prove functions using the vertical line test on a graph (no given value of x should result in 2 values)

Functions can be even, odd, or neither:

• Even: f(-x) = f(x)
• Odd: f(-x) = -(f(x))
• Neither: Both of the obove conditions are false

Even: symmetrical about the y access Odd: symmetrical about the origin

Operations

You can do all the normal operations with functions

f(x) = x^2 + 4
g(x) = x - 2

(f + g)(x) = (x^2 + 4) + (x - 2)
fg(x) = (x^2 + 4)(x - 2) = x^3 -2x^2 + 4x - 8