The least numerical value, either positive or negative of angle `theta` is called principal value of the inverse trigonometric function.

Explanation

To determine whether the statement "The least numerical value, either positive or negative of angle theta is called principal value of the inverse trigonometric function" is true or false, we can analyze the definition of the principal value in the context of inverse trigonometric functions.

### Step-by-Step Solution:

1. **Understanding the Principal Value**:
- The principal value of an inverse trigonometric function refers to the specific range of angles that the function can take. For example, for the arcsine function (sin^(-1)), the principal value is typically taken to be in the range of [-π/2, π/2].

2. **Identifying the Range**:
- Each inverse trigonometric function has a defined range where it returns values. For instance:
- arcsin(x) has a range of [-π/2, π/2]
- arccos(x) has a range of [0, π]
- arctan(x) has a range of (-π/2, π/2)

3. **Analyzing the Statement**:
- The statement mentions "the least numerical value, either positive or negative". This suggests that we are considering both positive and negative angles. However, in the context of inverse trigonometric functions, the principal value is not merely about the least numerical value but rather the defined range of angles for each function.

4. **Conclusion**:
- The statement is misleading because it implies that the principal value is simply the least numerical value without considering the specific ranges defined for each inverse trigonometric function. Therefore, the statement is **false**.

### Final Answer:
The statement "The least numerical value, either positive or negative of angle theta is called principal value of the inverse trigonometric function" is **false**.