Indian cosine of course! This Ottawa restaurant was located on Bronson Avenue, just north of the Queensway.
The Indian "Sine " function is defined in terms of the chords in a circle and thus depends on the radius of the circle. More precisely if x is the angle formed by two radii of a circle, then we look at chord(2x), the chord formed by twice the angle, then:
Sin(x) = 1/2 * chord(2x)
As far as I am aware the Indian Cosine function was never explicitly defined.