Giải câu 2 bài 2: Quy tắc tính đạo hàm.
a) \(y = x^5- 4 x^3+ 2x - 3\)
\(\Rightarrow y' = 5x^4- 4.3x^2+ 2=5x^4- 12x^2+ 2\)
b) \(y = \frac{1}{4} - \frac{1}{3}x + x^2 - 0,5x^4\)
\(\Rightarrow y' = - \frac{1}{3} + 2x - 0,5.4x^3 = - \frac{1}{3} + 2x - 2x^3\)
c) \(y = \frac{x^{4}}{2}- \frac{2x^{3}}{3}+ \frac{4x^{2}}{5} - 1\)
\(\Leftrightarrow y = \frac{1}{2}x^4 - \frac{2}{3}x^{3}+ \frac{4}{5}x^{2} - 1\)
\(\Rightarrow y' = 4.\frac{1}{2}x^3- 3.\frac{2}{3}x^2+ 2.\frac{4}{5}x\)
\(\Rightarrow y' = 2x^3- 2x^2+ \frac{8}{5}x\)
d) \(y = 3x^5(8 - 3x^2)\).
\(\Leftrightarrow y = 24x^5- 9x^7\)
\(\Rightarrow y' = 5.24x^4-9.7x^6=120x^4- 63x^6\).