函数 $y=sinx -x$的微分为
A: $cos x -1 $
B: $(cos x -1)dx$
C: $(sin x -1)dx$
D: $sin x -1$
A: $cos x -1 $
B: $(cos x -1)dx$
C: $(sin x -1)dx$
D: $sin x -1$
举一反三
- 求函数[img=107x38]17da6537b12a2e0.png[/img]的导数； ( ) A: 2*x*sin(1/x) - sin(1/x) B: 2xsin(1/x) - cos(1/x) C: 2*x*sin(1/x) - cos(1/x) D: 2*x*cos(1/x) - cos(1/x)
- 已知\( y = \sin x + \cos x \),则 \( dy = (\cos x - \sin x)dx \)（ ）.
- \( \int { { {\cos 2x} \over {\sin x - \cos x}}dx} = \)( ) A: \(\sin x + \cos x + C \) B: \( - \sin x + \cos x + C \) C: \( - \sin x- \cos x + C \) D: \( \sin x - \cos x + C \)
- 函数\(y = \sin {1 \over x}\)的导数为（ ）. A: \({1 \over { { x^2}}}\sin {1 \over x}\) B: \( - {1 \over { { x^2}}}\sin {1 \over x}\) C: \( - {1 \over { { x^2}}}\cos {1 \over x}\) D: \({1 \over { { x^2}}}\cos {1 \over x}\)
- $\int {{1 \over {3 + 5\cos x}}} dx = \left( {} \right)$ A: ${1 \over 4}\ln \left| {{{2\cos x + \sin x} \over {2\cos x - \sin x}}} \right| + C$ B: ${1 \over 4}\ln \left| {{{2\cos {x \over 2} + \sin {x \over 2}} \over {2\cos {x \over 2} - \sin {x \over 2}}}} \right| + C$ C: $\ln \left| {{{\cos {x \over 2} + \sin {x \over 2}} \over {\cos {x \over 2} - \sin {x \over 2}}}} \right| + C$ D: $\ln \left| {{{\cos x + \sin x} \over {\cos x - \sin x}}} \right| + C$