题目内容

句子翻译(手写并拍照上传):In this phase,the computer replaces some expensive optical and mechanical components by substituting analog measurement and calculation with mathematical computation to solve the relationship between the coordinates of an image point observed in the photographic two-dimensional coordinated system and the coordinates of an object photographed in the object 3D coordinate system.

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若sinαcosα<0,则α的终边在( )

A. 第一或第二象限
B. 第一或第三象限
C. 第一或第四象限
D. 第二或第四象限

在平面直角坐标系中,角α的顶点在原点,始边与x轴的正向重合,终边与单位圆的交点为P1(x,y),角α+θ的终边与单位圆的交点为P2(y,-x),则下列说法中正确的是( )

A. sin(α+θ)=sinα
B. sin(α+θ)=-cosα
C. cos(α+θ)=-cosα
D. cos(α+θ)=-sinα

sin(-660°)( )0

A. ≥
B. <
C. >
D. ≤

sin(-420°)cos570°( )0

A. ≥
B. <
C. >
D. ≤

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