The opposite reciprocal of 3 is -1/3.
Here’s how we find it: First, understand that the reciprocal of a number is 1 divided by that number. So, the reciprocal of 3 is 1/3. Then, to find the opposite reciprocal, we need to take that value and change its sign. Since the reciprocal is 1/3, its opposite is -1/3. Therefore, the opposite reciprocal of 3 is -1/3.