Math
Inverse cosine. It returns the angle whose cosine is the input value. Keep the input normally between -1.0 and 1.0 to avoid invalid mathematical results.
Input should normally be between -1.0 and 1.0.
acos(0.25)
For pitched oscillator functions, X already contains the current MIDI note pitch and transpose information. Prefer saw(X), sin(X), or pwm(X, 0.4) unless you intentionally want an octave or ratio shift such as 0.5*X or 2*X.