太慘了， 我又手賤翻了另外一本比較通俗的 Calculus, Finney 跟 Thomas寫的，第639頁他竟然寫

because c/a = 2c/2a <= 是不是錯的很離譜 ？

第682頁寫 we subtract the integral of (1/2)r^2 <= 畫蛇添足

有一個好消息是這本書的第 x 頁 寫到 :

Some of our colleagues suggested that since we are so confident about the book's accuracy, we should go one step further, and offer payment for any remaining errors that are found. With this in mind, but primarily because we want to detect any remaining errors quickly and correct them in subsequent printings, we are offering to pay $5 per mathematical error to the first person who reports the error. Any mathematical error that has follow-through effects will be counted as at most two errors.

說不定可以賺點外快。 不過我手邊的是第二板，完全不記得是那時在曉圓買的，有更新版本的網友可以看一下，看看更新版本的有沒有改過，說不定錢被賺走了。