Transformations of Sine and Cosine
You can change how sine and cosine graphs look using the formula y = a·sinb(x−c)+d (or cosine instead of sine). Each letter in this formula controls a different aspect of the wave's appearance.
The value a determines the amplitude (height) of the wave. For example, y = 3sin(2x) has an amplitude of 3, meaning the wave stretches 3 units above and below its midline. The period is controlled by b using the formula 2π/b. In y = 3sin(2x), the period is π, making the wave complete its cycle faster than normal.
Horizontal shifts (c) move the entire wave left or right, while vertical shifts (d) move it up or down. In y = cosx/2+1, the amplitude stays 1, but the period extends to 4π (making a wider wave), and the entire graph shifts up 1 unit, giving a range of 0,2.
Remember: When working with transformed trig functions, start by identifying each component (a, b, c, d) and understand how each affects the graph. Period = 2π/b is especially important for determining wave width!
When graphing these transformations, calculate key points over one complete cycle. This gives you enough information to sketch the entire function, since the pattern will repeat infinitely in both directions.