For this case we have that by definition:
[tex]Sin (90) = 1\\Cos (90) = 0[/tex]
Now, the tangent of 90 is given by:
[tex]tg (90) = \frac {Sin (90)} {Cos {90}} = \frac {1} {0}[/tex]
Thus, it is observed that the tangent of 90 degrees is not defined. Is obtained ∞.
Similarly:
[tex]Sin (-90) = - 1\\Cos (-90) = 0[/tex]
Now, the tangent of -90 is given by:
[tex]tg (-90) = \frac {Sin (-90)} {Cos {-90}} = \frac {-1} {0}[/tex]
Thus, it is observed that the tangent of -90 degrees is not defined.
Answer:
False
