Question

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＿＿＿?

Answer 1

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/5

sinα=sinπ/5 / R=sinπ/5 α=π/5

3 π/8=tanwx

π/8=tanw(x+π/8)

tanwx=tanw(x+π/8)

w=8

f(π/8)=tanπ