## Trigonometry (11th Edition) Clone

No, $\tan^{-1}$x is not the reciprocal of $\tan x.$ (It is the inverse of tan)
Entering $\tan^{-1}25^{o}$, the calculator returns 87.7093899574, which is the angle (in degrees) for which tan is 25. To check, enter $\tan($87.7093899574$)$.... result=25. To get $\cot 25^{o}$, he should have entered $(\tan 25)^{-1}$ or $1/\tan 25$ with the result : 2.14450692051 $\tan^{-1}$x is not the reciprocal of $\tan x.$ (It is the inverse of tan)