Step 1: Definition of onto function.
An onto function (also called surjection) is a function in which every element of the codomain (set $Y$) has a pre-image in the domain (set $X$). This means that for every $y \in Y$, there exists an $x \in X$ such that $f(x) = y$.
Step 2: Range of an onto function.
Since an onto function maps every element of $Y$ to at least one element in $X$, the range of $f$ will cover the entire set $Y$. Hence, the range of $f$ is $Y$.
Step 3: Conclusion.
Therefore, the correct answer is (C) $Y$.
A relation \( R = \{(a, b) : a = b - 2, b \geq 6 \} \) is defined on the set \( \mathbb{N} \). Then the correct answer will be:
The principal value of the \( \cot^{-1}\left(-\frac{1}{\sqrt{3}}\right) \) will be: