# *Sin & cos as projections

***Sin & cos as projections**

Actually cos & sin gives us an ideas of projections (shadows) of a line on x & y axis respectively. Consider a line of length L making an anticlockwise angle q with + x axis. Let L_{x} (= ON) &L_{y} (= OM) be its x & y projections, then

If θ is increased from 0^{0} to 90^{0}, then cosθ decreases & sinθ increases.

sin^{2} θ + cos^{2} θ = 1

cosec^{2} θ – cot^{2 θ} = 1

For integral values of n