Constants Rule
Recipe: The derivative of a constant is always zero.
This is a very straightforward idea, but one that has to be mentioned.
Remember that derivatives are all about telling us how much something is changing.
Since a constant is not changing , it is a constant, the amount of change that is occurring is zero, there is no slope. The derivative of a constant is always zero. If we think about this in terms of a graph, the graph of a constant is a horizontal line and the slope of a horizontal line, a constant,will always be zero.