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Sine

sine
sin

The trig function sine, written sin θ. For acute angles, sin θ can be found by the SOHCAHTOA definition as shown below on the left. The circle definition, a generalization of SOHCAHTOA, is shown below on the right. Finally, f(x) = sin x is a periodic function with period 2π.

 

Two diagrams defining sine: SOHCAHTOA triangle with sinθ=opposite/hypotenuse; unit circle with point (x,y) showing sinθ=y/r.

 

 

See also

Inverse sine, sinusoid, angle