函数y=sin2x， 则dy=__________.
举一反三
- 已知\( y = \sin x + \cos x \),则 \( dy = (\cos x - \sin x)dx \)（ ）.
- 函数y=sin(－2x)＋sin2x A: B: C: 2 D: 4
- 曲线积分$$\int_{(0,0}^{(x,y)}(2x\cos y-y^2\sin x)dx+(2y\cos x-x^2\sin y)dy=$$ A: $y^2\cos x+x^2\cos y$ B: $x^2\cos x+y^2\cos y$ C: $x^2\sin y+y^2\sin x$ D: $x^2\sin x+y^2\sin y$
- 3. $(2x\cos y-{{y}^{2}}\sin x)dx+(2y\cos x-{{x}^{2}}\sin y)dy$的原函数是 ( ) A: ${{x}^{2}}\sin y-{{y}^{2}}\sin x+C$ B: ${{x}^{2}}\sin y+{{y}^{2}}\sin x+C$ C: ${{x}^{2}}\cos y-{{y}^{2}}\cos x+C$ D: ${{x}^{2}}\cos y+{{y}^{2}}\cos x+C$
- 函数y=sin2x,在[img=43x41]17e0a855ff67be3.png[/img],Δx=0.01时的微分dy=0.01。( )