a) \[ f_1'(x) = \cos(3x^2) \cdot 6x \]
b) \[ f_2'(x) = -2x \cdot \tan(x^2)\]
c) \[ f_3'(x) = e^{x^3} \cdot 3x^2 \]
d) \[ f_4'(x) = \frac{5x^4}{\sqrt{2x^5 + 1}} \]
e) \[ f_5'(x) = \frac{1}{x \cdot \cos^2(\ln(x))} \]
f) \[ f_6'(x) = -\frac{2x + 2e^{2x}}{(x^2 + e^{2x})^2} \]
g) \[ f_7'(x) = \frac{\cos(\sqrt{x})}{2\sqrt{x}} \]
h) \[ f_8'(x) = \frac{1 - 3\ln(x)}{x^4} \]