论文部分内容阅读
空间角是空间图形的一个要素,在异面直线所成的角、线面角、二面角等知识点上,较好地考查了同学们的逻辑推理能力以及化归的数学思想三种空间角的向量法计算公式(直线a、b的方向向量为a、b):(1)异面直线a,b所成的角为θ,则cosθ=|cos|。(2)直线a与平面a(法向量为n)所成的角为β,则sinθ=|cos|。(3)锐二面角θ:cosθ=|cos|,其中m,n为两个面的法向量。
Spatial angle is one of the elements of the space graph. The knowledge angle of angle, line angle, dihedral angle and other points formed by the straight lines of the different sides better examines the students’ logical reasoning ability and the three kinds of mathematical thoughts Angle vector method (a, b of the direction vector a, b): (1) different surface straight line a, b the angle formed by θ, then cos θ = | cos |. (2) The angle formed by the line a and plane a (normal vector n) is β, then sin θ = | cos |. (3) Sharp dihedral angle θ: cos θ = | cos |, where m and n are normal vectors of two planes.