The expression "f (x)" means "a formula, named f, has x as its input variable" It does not mean "multiply f and x "!Derivative definition The derivative of a function is the ratio of the difference of function value f (x) at points xΔx and x with Δx, when Δx is infinitesimally small The derivative is the function slope or slope of the tangent line at point xSwitch the x's and y's At this point you are dealing with the inverse;
Functions And Their Inverses Worked Examples