圆心角的弧度数等于它对的弧长,以1弧度作为角的单位,那么周角的大小就是2π弧度,因而π就相当于180°角的弧度值.
弧长＝r×π/3＝2π/3
角度＝弧长/r＝1
猜你喜欢
- 1complete the following ,and then give short answers
- 2b为实数,且1+bi/2与1/2的实部与虚部相等 求b=?
- 3一种油菜籽每10千克可以榨出3千克食用油.照这样计算,1口屯油菜籽可以榨油多少千克?
- 41．What do you think of “If You are the One”,the __________TV show?
- 5nose to nose/back to back的中文
- 6If my sister hadn't thought it over and over before making the decision,she______ a mistake.
- 7下列各点中,即位于西半球,又位于南半球的是?
- 8I____find my math book.Where isit?Do you know? A.It's B.do C.isn't D.can't
- 9x^3-3x[1/3x-2(1/2x+2)],其中x=-2(先化简,再求值）
- 10一条鱼的质量是等于自身的4分之3加4分之3千克,这条鱼的质量是几千克?