11. The position vector to a curve in R3 is given by
What is the unit tangent vector at t = Pi/3 ?
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A.
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B.
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C.
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D.
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E.
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Solution: The answer is B
The tangent vector at t = Pi/3 can be found by evaluating the value of the derivative of each component of the position vector at t = Pi/3, as follows:
The magnitude of the above vector is,
Unitize the above vector by dividing each component by it’s own magnitude, so that the unit tangent vector is given by,
