Math basics › Trigonometry
Graphs of sine and cosine
y = a sin(b(x − c)) + d
|a| is the amplitude, the period is 2π/b, c shifts it sideways and d shifts it up.
Sine and cosine are the same wave
Cosine is sine shifted left by π/2. Sine starts at 0, cosine starts at its maximum.
Tangent is different
Period π, no amplitude, and vertical asymptotes wherever cos = 0.