Question

How do you calculate the `arctan(-1)`?

Answer 1

`arctan(−1)=(npi-pi/4)`, where `n` is an integer i.e. `arctan(−1)` can take values such as `{.......,-9pi/4,-5pi/4,-pi/4,3pi/4,7pi/4,.....}`

Explanation:

`arctan(−1)` is the angle whose tangent is `-1`.

As `tan(-pi/4)=-tan(pi/4)=-1` and tangent of angle has a cycle of `p` radians

We can generally put `arctan(−1)=(npi-pi/4)`, where `n` is an integer i.e. `arctan(−1)` can take values such as `{.......,-9pi/4,-5pi/4,-pi/4,3pi/4,7pi/4,.....}`