Cartesian Coordinate Systems - 3D Math Primer for Graphics and Game Development - page 30

11. Confirm the following:
(a) (sin(α)/ csc(α)) + (cos(α)/ sec(α)) = 1
(b) (sec 2 (θ)−1)/ sec 2 (θ) = sin 2 (θ)
(c) 1 + cot 2 (t) = csc 2 (t)
(d) cos(φ)(tan(φ) + cot(φ)) = csc(φ)
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