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How do you verify the identity $cot (θ - \frac{π}{2}) = - tan θ$ $cot (theta-pi/2)=-tan theta$ ?

1 Answer

May 3, 2015

Properties of complement arcs:

$cot (\frac{π}{2} - a) = tan a$ $cot (pi/2 - a) = tan a$

Then, $- cot (\frac{π}{2} - a) = cot (a - \frac{π}{2}) = - tan a .$ $-cot (pi/2 - a) = cot (a - pi/2) = -tan a.$

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