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| Identical properties of circular functions and trigonometric functions |
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Let O be the origin. Let OA be the unit radius of the circle drawn with O as centre. Let OA trace an angle when OA takes the position OP. Then
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| The tracing of the angle q and the arc AP = P(q) are one and the same. |
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| Let the co-ordinates of P be (x, y). |
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| Draw PM perpendicular to x-axis. |
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| By the definition of Circular functions, we have |
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| \ The Circular
function of a real number q and the
trigonometric function for the angle qc are same. |
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| From the above property, the identities for circular functions of real numbers hold for trigonometric functions of angle q. |
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