> Why were sine, cosine, and tangent all positive in the first quadrant, while only sine was in the second quadrant? You were not endlessly drilled with diagra

> Why were sine, cosine, and tangent all positive in the first quadrant, while only sine was in the second quadrant? You were not endlessly drilled with diagrams of circles that made the signs obvious? Trigonometry without diagrams is like pie without fruit!