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            • 1. 在同一平面直角坐标系中,经过坐标伸缩变换后,曲线C变为曲线2x′2+8y′2=1,则曲线C的方程为(  )
              A.50x2+72y2=1
              B.50x2+72y2=1
              C.25x2+36y2=1
              D.
            • 2. 在同一平面直角坐标系中,将曲线y=cos2x按伸缩变换变换为(  )
              A.y′=cosx′
              B.y′=cosx′
              C.y′=2cosx′
              D.y′=cos3x′
            • 3.

              将曲线\(C\)按伸缩变换公式\(\begin{cases}x{{{"}}}=2x \\ y{{{"}}}=3y\end{cases} \)变换后的曲线方程为\((x{{"}})^{2}+(y{{"}})^{2}=1\),则曲线\(C\)的方程为 \((\)     \()\)

              A.\(\dfrac{{x}^{2}}{4}+ \dfrac{{y}^{2}}{9}=1 \)
              B.\(\dfrac{{x}^{2}}{9}+ \dfrac{{y}^{2}}{4}=1 \)
              C.\(4{x}^{2}+9{y}^{2}=36 \)
              D.\(4{x}^{2}+9{y}^{2}=1 \)
            • 4.

              在同一坐标系中,将曲线\(y=2\sin 3x\)变为曲线\(y=\sin x\)的伸缩变换是(    )

              A.  \(\begin{cases} & x=3{x}{{{"}}} \\ & y=\dfrac{1}{2}{y}{{{"}}} \end{cases}\)
              B.\(\begin{cases} & {x}{{{"}}}=3x \\ & {y}{{{"}}}=\dfrac{1}{2}y \end{cases}\)
              C.\(\begin{cases} & x=3{x}{{{"}}} \\ & y=2{y}{{{"}}} \end{cases}\)
              D.\(\begin{cases} & {x}{{{"}}}=3x \\ & {y}{{{"}}}=2y \end{cases}\)
            • 5.

              将椭圆\(\dfrac{{{x}^{2}}}{9}+\dfrac{{{y}^{2}}}{4}=1\)按\(φ:\begin{cases} & x{{{"}}}=\lambda { }x(\lambda > 0) \\ & y{{{"}}}=\mu { }y{(}\mu > {0)} \end{cases}\) ,变换后得到圆\(x{{{{{"}}}}^{2}}+y{{{{{"}}}}^{2}}=9\),则\((\)  \()\)

              A.\(λ=3\), \(μ=4\)       
              B.\(λ=3\),\(μ=2\)
              C.\(λ=1\), \(μ=\dfrac{2}{3}\)
              D.\(λ=1\),\(μ=\dfrac{3}{2}\)
            • 6.

              已知曲线\(C\)的极坐标方程为\(\rho^{2}{=}\dfrac{12}{3\cos^{2}\theta{+}4\sin^{2}\theta}\),以极点为原点,极轴为\(x\)轴非负半轴建立平面直角坐标系,则曲线\(C\)经过伸缩变换\(\begin{cases}{x}^{,}= \dfrac{1}{2}x \\ {y}^{,}= \dfrac{ \sqrt{3}}{3}y\end{cases} \)后,得到的曲线是\((\)    \()\)

              A.直线        
              B.椭圆        
              C.双曲线      
              D.圆
            • 7.

              将曲线\(C\)按伸缩变换公式\({ }\!\!\{\!\!{ }\begin{matrix} {x}{{{"}}}=2x \\ {y}{{{"}}}=3y \\\end{matrix}{ }\)变换后的曲线方程为\({{\left( {{x}{{{"}}}} \right)}^{2}}+{{\left( {{y}{{{"}}}} \right)}^{2}}=1\),则曲线\(C\)的方程为 \((\)     \()\)

              A.\(\dfrac{{{x}^{2}}}{4}+\dfrac{{{y}^{2}}}{9}=1\)
              B.\(\dfrac{{{x}^{2}}}{9}+\dfrac{{{y}^{2}}}{4}=1\)
              C.\(4{{x}^{2}}+9{{y}^{2}}=36\)
              D.\(4{{x}^{2}}+9{{y}^{2}}=1\)
            • 8.
              在同一坐标系中,将曲线\(y=3\sin 2x\)变为曲线\(y′=\sin x′\)的伸缩变换是\((\)  \()\)
              A.\( \begin{cases} x=2x′ \\ y= \dfrac {1}{3}y′\end{cases}\)
              B.\( \begin{cases} x′=2x \\ y′= \dfrac {1}{3}y\end{cases}\)
              C.\( \begin{cases} x=2x′ \\ y=3y′\end{cases}\)
              D.\( \begin{cases} x′=2x \\ y′=3y\end{cases}\)
            • 9.

              欲将方程\(\dfrac{{{x}^{2}}}{4}+\dfrac{{{y}^{2}}}{3}=1\)所对应的图形变成方程\({{x}^{2}}+{{y}^{2}}=1\)所对应的图形,需经过伸缩变换\(\varphi \)为\((\)  \()\)

              A.\(\begin{cases} & {x}{{"}}=2x \\ & {y}{{"}}=\sqrt{3}y \\ \end{cases}\)
              B.\(\begin{cases} & {x}{{"}}=\dfrac{1}{2}x \\ & {y}{{"}}=\dfrac{\sqrt{3}}{3}y \\ \end{cases}\)
              C.\(\begin{cases} & {x}{{"}}=4x \\ & {y}{{"}}=3y \\ \end{cases}\)
              D.\(\begin{cases}{x}^{{{"}}}= \dfrac{1}{4}x \\ {y}^{{{"}}}= \dfrac{1}{3}y\end{cases} \)
            • 10. y=cosx经过伸缩变换后,曲线方程变为(  )
              A.y′=3cos 
              B.y′=3cos 
              C.y′=cos 
              D.y′=cos 2x′
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