The "reciprocal" of a number is just 1 divided by that number.
The reciprocal of \(x\) is \(\frac1x\) . The reciprocal of \(\frac{a}{b}\) is \(\frac{b}{a}\) .
But the slopes of perpendicular lines are not just reciprocals of each other.
The slopes of perpendicular lines are negative reciprocals of each other. To find the slope of a line perpendicular to one with a given slope, we must take the negative reciprocal of the given slope. That means take the reciprocal of the slope and also multiply it by -1 .
For example...
If a line has a slope of \(\frac34\) , the slope of a line perpendicuar = -\(\frac43\)
Take a look at this graph to see if the slope of the blue line is just \(\frac43\) , it is not perpendicular to the red line, but if you change it to -\(\frac43\) , then it is perpendicular: http://www.desmos.com/calculator
I don't think I understand what your specific examples are.....Does this help though?
If not please don't hesitate to ask another question!