First of all, you should understand the concept that if there is a derivative somewhere in the function, then the derivative here is the slope of the tangent line passing through it. For example, if the derivative of y=xx is y'=2x, it means that the tangent slope at x= 1 is 2 and the tangent slope at x=2 is 4. There are two answers and cases. For example, yy=x, or Y = √ X, then Y' =+ 1/(2 √ x). As for the term "tangent of derivative", it is not accurate.