Derivatives)

Exercise

1.
Find the derivative of the following functions using the definition of derivative.
(a)
$\displaystyle{f(x) = \cos{3x}}$
(b)
$\displaystyle{f(x) = (x + 2)^{n} \ (n : \mbox{integer})}$
2.
Find the defivative of the following funciton.
(a)
$\displaystyle{f(x) = x^4}$
(b)
$\displaystyle{f(x) = e^{x}}$
3.
Find the right-hand and left-hand derivative at $x = 0$.
(a)
$\displaystyle{f(x) = \vert x^2 + x\vert}$
(b)
$\displaystyle{f(x) = \left\{\begin{array}{ll}
x^2 \sin{\frac{1}{x}}, & x \neq 0\\
0, & x = 0
\end{array}\right.}$
(c)
$\displaystyle{f(x) = \sqrt{x^3 + x^2}}$