# How do you calculate sin^-1(9.4 / 12)?

Feb 12, 2016

$51.57$ degrees as also $128.43$ degrees.

#### Explanation:

Sine of an angle can take value between $- 1$ and $+ 1$.

As $\frac{9.4}{12} = 0.78333$, the angle whose sine is $0.78333$ is ${\sin}^{-} 1 \left(\frac{9.4}{12}\right)$.

Using a scientific calculator this comes out to $51.57$ degrees. It can also be $180 - 51.57$ i.e. $128.43$ too as $\sin \left(\pi - \theta\right) = \sin \theta$.

One can add multiples of 360 degrees too as it does not affect sine of an angle.