# How do you find the value for arctan(1)?

##### 1 Answer
Jul 2, 2015

It would be ${45}^{o}$ or $\frac{\pi}{4} r a d$

#### Explanation:

$\arctan \left(1\right)$ means: find the angle that belongs to a ratio of opposite side divided by adjoining side (in a rectangular triangle) of $1$.
Or in other words: where the opposite and adjoining sides are equal.
This only happens in an isosceles rectangular triangle, where both other angles are one half of a right angle, i.e. ${45}^{o}$ or $\frac{\pi}{4} r a d$