How do you tell whether the value of tan 90 degrees is positive, negative, zero or undefined?

1 Answer
Mar 7, 2018

Undefined

Explanation:

We have:

#tan90^@#

Know that, #tantheta=(sintheta)/(costheta)#

So here, we get

#tan90^@=(sin90^@)/(cos90^@)#

Looking at the trigonometric table, we see that #sin90^@=1,cos90^@=0#.

![http://www.omtexclasses.com/2011/06/http://trigonometric-table.html](https://useruploads.socratic.org/ws6S61qVTnSs2xNBFWik_Trigonometric%20Table.png)

Therefore,

#tan90^@=1/0#

Since anything divided by #0# (except #0# itself) is considered to be undefined, we get that #tan90^@# is undefined as well.