1.已知弧度数为2的圆心角多对的弦长也是2,则这个圆心角所对的弧长是＿＿＿?

题目

1.已知弧度数为2的圆心角多对的弦长也是2,则这个圆心角所对的弧长是＿＿＿?
2.设α角的终边上一点P的坐标是（cosπ/5,sinπ/5）,则α等于＿＿＿?
3.f（x）=tanwx（w>0）的图象的相邻两支截直线y=π/8所得线段长为π/8,则f(π/8)的值是＿＿＿

答案

1 圆心角为 2/2π*360=360/π 半径R=1/SIN(180/π)弧长L=R 360/π =360/π SIN(180/π)2 R=COS^2π/5+SIN^2π/5sinα=sinπ/5 / R=sinπ/5 α=π/53 π/8=tanwxπ/8=tanw(x+π/8)tanwx=tanw(x+π/8)w=8 f(π/8)=tan...