Differentiate the following from first principles
We need to find derivative of f(x) = x2 ex
Derivative of a function f(x) is given by –
f’(x) = {where h is a very small positive number}
∴ derivative of f(x) = x2 ex is given as –
f’(x) =
⇒ f’(x) =
⇒ f’(x) =
Using algebra of limits, we have –
⇒ f’(x) =
⇒
As 2 of the terms will not take indeterminate form if we put value of h = 0, so obtained their limiting value as follows –
∴ f’(x) = 0×ex + 0 + 2x ex + 0 +
Use the formula:
⇒ f’(x) = 2x ex + x2 ex
⇒ f’(x) = 2x ex + x2 ex
Hence,
Derivative of f(x) = x2 ex = 2x ex + x2 ex