基本求导公式
基本求导公式
$$1. \ (x^\alpha)^{\prime} \ = \ ax^{a \ - \ 1}$$
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$$2. \ (a^x)^{\prime} \ = \ (a^x)\ln{a} \ \ \ (a>0, \ a \neq 1)$$
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$$3. \ (e^x)^{\prime} \ = \ e^x$$
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$$4. \ (log_ax)^{\prime} \ = \ \frac{1}{x\ln{a}} \ \ \ (a>0,a \neq 1)$$
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$$5. \ (\ln{x})^{\prime} \ = \ \frac{1}{x}$$
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$$6. \ (sinx)^{\prime} \ = \ cosx$$
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$$7. \ (cosx)^{\prime} \ = \ -sinx$$
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$$8. \ (\arcsin{x})^{\prime} \ = \ \frac{1}{\sqrt{1 \ - \ x^2}}$$
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$$9. \ (\arccos{x})^{\prime} \ = \ -\frac{1}{\sqrt{1 \ - \ x^2}}$$
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$$10. \ (\tan{x})^{\prime} \ = \ \sec{^2x}$$
证明:
$(\tan{x})^{\prime}$
$= \ (\frac{\sin{x}}{\cos{x}})^{\prime}$
$= \ \frac{\cos{x} \cos{x} \ - \ \sin{x}(-\sin{x})}{\cos{^2x}}$
$= \ \frac{1}{\cos{^2x}}$
$= \ \sec{^2x}$
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$$11. \ (\cot{x})^{\prime} \ = \ -\csc{^2x}$$
证明:
$(\cot{x})^{\prime}$
$= \ (\frac{\cos{x}}{\sin{x}})^{\prime}$
$= \ (\frac{-\sin{x} \sin{x} \ - \ \cos{x} \cos{x}}{\sin{^2x}})$
$= \ -\frac{1}{\sin{^2x}}$
$= \ -\csc{^2x}$
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$$12. \ (\arctan{x})^{\prime} \ = \ \frac{1}{1 \ + \ x^2} \ \ \ (暂时不会证明)$$
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$$13. \ (arccot{x})^{\prime} \ = \ -\frac{1}{1 \ + \ x^2}$$
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$$14. \ (\sec{x})^{\prime} \ = \ \sec{x} \tan{x}$$
证明:
$(\sec{x})^{\prime}$
$= \ (\frac{1}{\cos{x}})^{\prime}$
$= \ \frac{0 \ - \ (-\sin{x})}{\cos{^2x}}$
$= \ \frac{sin{x}}{cos{x}} \frac{1}{\cos{x}}$
$= \ \sec{x} \tan{x}$
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$$15. \ (\csc{x})^{\prime} \ = \ -\csc{x} \cot{x}$$
证明:
$(\csc{x})^{\prime}$
$= \ (\frac{1}{\sin{x}})^{\prime}$
$= \ \frac{0 \ - \ \cos{x}}{\sin{^2x}}$
$= \ -\frac{\cos{x}}{\sin{x}} \frac{1}{\sin{x}}$
$= \ -\csc{x} \ \cot{x}$
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$$16. \ [\ln{(x \ + \ \sqrt{x^2 \ + \ 1}})]^{\prime} \ = \ \frac{1}{\sqrt{x^2 \ + \ 1}}$$
证明:
$[\ln{(x \ + \ \sqrt{x^2 \ + \ 1}})]^{\prime}$
$= \ \frac{1 \ + \ \frac{1}{2}\frac{2x}{\sqrt{x^2 \ + \ 1}}}{x \ + \ \sqrt{x^2 \ + \ 1}}$
$= \ \frac{1 \ + \ \frac{x}{\sqrt{x^2 \ + \ 1}}}{x \ + \ \sqrt{x^2 \ + \ 1}}$
$= \ \frac{\frac{x \ + \ \sqrt{x^2 \ + \ 1}}{\sqrt{x^2 \ + \ 1}}}{x \ + \ \sqrt{x^2 \ + \ 1}}$
$= \ \frac{1}{\sqrt{x^2 \ + \ 1}}$
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$$17. \ [\ln{(x \ + \ \sqrt{x^2 \ - \ 1}})]^{\prime} \ = \ \frac{1}{\sqrt{x^2 \ - \ 1}}$$