# Arctan Scalar

**Node Description & Purpose:**
These nodes output the arc cosine, arc sine or arc tangent of the Input scalar. These are the inverse cosine, inverse sine or inverse tangent of the Input scalar, respectively. Using arc sine as an example, the inverse sine of a value is the number which is the sine of the value. Put another way :

The sine of 1 is 0.017452

The arc sine, or inverse sine, of 0.017452 is 1

The output of this function is in radians. You can use the Radians to degrees scalar node to convert the output to degrees.

It is important to note that for correct results the input to the Arccos scalar node and Arcsin scalar node needs to be between -1 and 1. TG2 doesn't check for this at the time of writing. You can use the Clamp scalar node with a Min value of -1 and a Max value of 1 to ensure this.

**Node Type:** Function

**Settings:**
These nodes have no other settings apart from the Input node.

**Error conditions:**

**Arccos scalar:**It is an error for the input value to be outside the range of -1 to 1. The output value is undefined in this situation.**Arcsin scalar:**It is an error for the input value to be outside the range of -1 to 1. The output value is undefined in this situation.

A scalar is a single number. 1, 200.45, -45, -0.2 are all examples of scalar values.

A single object or device in the node network which generates or modifies data and may accept input data or create output data or both, depending on its function. Nodes usually have their own settings which control the data they create or how they modify data passing through them. Nodes are connected together in a network to perform work in a network-based user interface. In Terragen 2 nodes are connected together to describe a scene.