Please-sirs-How-is-cot-tan-1-2-pi-

Question Number 54156 by Tawa1 last updated on 30/Jan/19

Please sirs, How is, - \cot (α) = \tan (\frac{1}{2} π + α) ? ? ? ?

Commented by turbo msup by abdo last updated on 30/Jan/19

t a n (\frac{π}{2} + α) = \frac{s i n (\frac{π}{2} + α)}{c o s (\frac{π}{2} + α)}

= \frac{c o s α}{- s i n α} = - \frac{1}{t a n α} = - c o t a n α .