The inverse, or the opposite of 1/2 is -1/2
If you look at a number line and point where 1/2 and -1/2 are, they are the same position away from 0, 1/2 away from 0.
Next, the distance should be doubled from 0, if your to find out the distance between both numbers
Therefore, the inverse or opposite of 1/2 is -1/2.
Hope this helps and have a great afternoon :))