问题
解答题
一个圆的半径扩大2倍，它的面积就比原来增加2倍______．
答案
设原来半径为r，则现在的半径为2r，
现在的面积÷原来的面积=π（2r）2÷（πr2）=（4πr2）÷（πr2）=4；
所以一个圆的半径扩大到原来的2倍，则它的面积扩大到原来的4倍．
故答案为：×．
搜题请搜索小程序“爱下问搜题”
一个圆的半径扩大2倍，它的面积就比原来增加2倍______．
设原来半径为r，则现在的半径为2r，
现在的面积÷原来的面积=π（2r）2÷（πr2）=（4πr2）÷（πr2）=4；
所以一个圆的半径扩大到原来的2倍，则它的面积扩大到原来的4倍．
故答案为：×．
In October, James Knight owned stock in Valerio, Inc. , that was valued at $45 per share. At that time, Knight sold a call option on Valerio with an exercise price of $60 for $1.45. In December, at expiration, the stock is trading at $32. What is Knight’s profit (or loss) from his covered call strategy Knight:
A．
| A. gained $11.55. |
B．
| B. lost $13.00. |
C．
| C. lost $11.55. |