Transformations of Trigonometric Functions
The transpformation of functions includes the shifting, stretching, and reflecting of their graph. The same rules apply when transforming trigonometric functions.
Vertical and Horizontal Shifts
Suppose c > 0. To obtain the graph of
y = f(x) + c: Shift the graph of y = f(x) up by c units
y = f(x) - c: Shift the graph of y = f(x) down by c units
y = f(x - c): Shift the graph of y = f(x) to the right by c units
y = f(x + c): Shift the graph of y = f(x) to the left by c units
Vertical and Horizontal Stretches/Compressions
Suppose c > 1. To obtain the graph of
y = cf(x): stretch the graph of y = f(x) vertically by a factor of c
y = 1/c f(x): compress the graph of y = f(x) vertically by a factor of c
y = f(cx): compress the graph of y = f(x) horizontally by a factor of c
y = f(x/c): stretch the graph of y = f(x) horizontally by a factor of c
Reflections
To obtain the graph of
y = -f(x): reflect the graph of y = f(x) about the x-axis; and
y = f(-x): reflect the graph of y = f(x) about the y-axis
Example 1:
Example 2: