# iarray.arccos#

iarray.arccos(iarr: IArray)#

Trigonometric inverse cosine, element-wise.

The inverse of cos so that, if $$y = \cos(x)$$, then $$x = \arccos(y)$$.

Parameters

iarr(self) (IArray container) – x-coordinate on the unit circle. For real arguments, the domain is $$\left [ -1, 1 \right]$$.

Returns

angle – A lazy expression that must be evaluated via out.eval(), which will compute the angle of the ray intersecting the unit circle at the given x-coordinate in radians $$[0, \pi]$$.

Return type

iarray.Expr

Notes

arccos is a multivalued function: for each $$x$$ there are infinitely many numbers $$z$$ such that $$\cos(z) = x$$. The convention is to return the angle $$z$$ whose real part lies in $$\left [ 0, \pi \right]$$.

References

np.arccos