![Elements of plane and spherical trigonometry . CQ) AP=AB -j- BP=AB -f BQ,AB = AC + CB = AO + CQ,AP + AB = AB -f AC + (BQ= a + Elements of plane and spherical trigonometry . CQ) AP=AB -j- BP=AB -f BQ,AB = AC + CB = AO + CQ,AP + AB = AB -f AC + (BQ= a +](https://c8.alamy.com/comp/2CE0G95/elements-of-plane-and-spherical-trigonometry-cq-ap=ab-j-bp=ab-f-bqab-=-ac-cb-=-ao-cqap-ab-=-ab-f-ac-bq=-a-b-c-=-2sbut-ap=ab-ap-=-s-hence-from-the-right-triangle-aop-rt-=-s-tan-ia-98-by-analogy-we-have-for-the-radii-of-the-other-two-escribedcirclesr-s-tan-ib-and-r-=-s-tan-jc-71-to-determine-a-point-xwithin-a-triangle-such-that-theangles-xab-xbg-andxca-shallbe-equal-and-to-show-that-if-d-bethis-angle-cot-8-=-cot-a-f-cot-b-j-cot-cfrom-the-figure-axb-=-180-d-b-d-bxc-=-180-c-cxa-=-180-a-180-5-100-plane-trigonometry-from-the-2CE0G95.jpg)
Elements of plane and spherical trigonometry . CQ) AP=AB -j- BP=AB -f BQ,AB = AC + CB = AO + CQ,AP + AB = AB -f AC + (BQ= a +
![Elements of plane and spherical trigonometry . angle is the reciprocal of thetangent of the angle. Thus, cot A AG AGXBG B,G etc. (8) The secant (sec) of an angle is Elements of plane and spherical trigonometry . angle is the reciprocal of thetangent of the angle. Thus, cot A AG AGXBG B,G etc. (8) The secant (sec) of an angle is](https://c8.alamy.com/comp/2CE0K06/elements-of-plane-and-spherical-trigonometry-angle-is-the-reciprocal-of-thetangent-of-the-angle-thus-cot-a-ag-agxbg-bg-etc-8-the-secant-sec-of-an-angle-is-the-reciprocal-of-the-cosineof-the-angle-thus-sec-a-=-=-a5l-=-etc-9-ag-abx-the-cosecant-esc-or-cosec-of-an-angle-is-the-reciprocal-of-the-sine-of-the-angle-thus-esc-a-=-ab-ab-bg-a-etc-10-the-trigonometric-functions-17-besides-these-six-functions-there-are-two-others-of-less-fre-quent-occurrence-called-the-versedsine-vers-and-coversedsinecovers-they-are-defined-by-the-following-equations-vers-a-=-1-c-2CE0K06.jpg)
Elements of plane and spherical trigonometry . angle is the reciprocal of thetangent of the angle. Thus, cot A AG AGXBG B,G etc. (8) The secant (sec) of an angle is
![Since $\tan(25\pi/2)$ is undefined, and $\cot x = \frac{1}{\tan x}$, then why isn't $\cot(25\pi/2)$ undefined instead of $0$? - Mathematics Stack Exchange Since $\tan(25\pi/2)$ is undefined, and $\cot x = \frac{1}{\tan x}$, then why isn't $\cot(25\pi/2)$ undefined instead of $0$? - Mathematics Stack Exchange](https://i.stack.imgur.com/tFfsY.gif)