Differentiating a function from first principles or “ab initio” means differentiating the function using the definition of derivative, only without making use of any theorem on differentiation, or derivative of standard forms.and get math homework help
Example: Differentiate tan-1 x from first principles.
Solution: Let y = tan-1x x = tan y
x + Δx = tan (y + Δy)
Let Δx 0 so that Δy 0. Then