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琦琦 寫到:為什麼課本的解答是125/3，和各位大大算的不大一樣!!

#ed_op#DIV#ed_cl#我用你那兩個方程, 輸入數學作圖軟體, 叫軟體給我下圖斜線的面積, 是 20.83333, 此值符合上面網友的計算值.#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl# #ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl##ed_op#IMG alt="image file name: 2kea98eeb309.png" src="http://yll.loxa.edu.tw/phpBB2/richedit/upload/2kea98eeb309.png" border=0#ed_cl##ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl# #ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#但是你的 125 / 3 = 41.6667.#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl# #ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#所以, 假如你沒誤打, 那麼你的課本就有誤錯了! 要不是題目有字印錯, 不然就是答案有字印錯.#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl##ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl##ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl##ed_op#/DIV#ed_cl#

為什麼課本的解答是125/3，和各位大大算的不大一樣!!

#ed_op#DIV#ed_cl##ed_op#SPAN id=convert149051#ed_cl##ed_op#SPAN class=postbody#ed_cl##ed_op#FONT size=1#ed_cl# #ed_op#/FONT#ed_cl##ed_op#DIV#ed_cl#f(x)=x#ed_op#SUP#ed_cl#2#ed_op#/SUP#ed_cl#-4,g(x)=2-x#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#x#ed_op#SUP#ed_cl#2#ed_op#/SUP#ed_cl#-4=2-x#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#x#ed_op#SUP#ed_cl#2#ed_op#/SUP#ed_cl#+x-6=0#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#(x+3)(x-2)=0#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#x=-3,2#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#∫(2-x-x#ed_op#SUP#ed_cl#2#ed_op#/SUP#ed_cl#+4)dx  | #ed_op#SUB#ed_cl#-3#ed_op#/SUB#ed_cl##ed_op#SUP#ed_cl#2#ed_op#/SUP#ed_cl##ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#∫-(x#ed_op#SUP#ed_cl#2#ed_op#/SUP#ed_cl#+x-6)dx  | #ed_op#SUB#ed_cl#-3#ed_op#/SUB#ed_cl##ed_op#SUP#ed_cl#2#ed_op#/SUP#ed_cl##ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#=-(x#ed_op#SUP#ed_cl#3#ed_op#/SUP#ed_cl#/3+x#ed_op#SUP#ed_cl#2#ed_op#/SUP#ed_cl#/2-6x) | #ed_op#SUB#ed_cl#-3#ed_op#/SUB#ed_cl##ed_op#SUP#ed_cl#2#ed_op#/SUP#ed_cl##ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#=-(8/3+4/2-12)+(-27/3+9/2+18)#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#=#ed_op#FONT color=#ff0000#ed_cl#20+5/6#ed_op#/FONT#ed_cl##ed_op#/DIV#ed_cl##ed_op#/SPAN#ed_cl##ed_op#/SPAN#ed_cl##ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl##ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl##ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl##ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl##ed_op#/DIV#ed_cl#

-3,2這個和解答一樣
但21+1/6和解答不一樣
解答的答案是

#ed_op#DIV#ed_cl#f(x)=x#ed_op#SUP#ed_cl#2#ed_op#/SUP#ed_cl#-4,g(x)=2-x#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#x#ed_op#SUP#ed_cl#2#ed_op#/SUP#ed_cl#-4=2-x#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#x#ed_op#SUP#ed_cl#2#ed_op#/SUP#ed_cl#+x-6=0#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#(x+3)(x-2)=0#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#x=-3,2#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#∫(2-x-x#ed_op#SUP#ed_cl#2#ed_op#/SUP#ed_cl#+4)dx  | #ed_op#SUB#ed_cl#-3#ed_op#/SUB#ed_cl##ed_op#SUP#ed_cl#2#ed_op#/SUP#ed_cl##ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#∫-(x#ed_op#SUP#ed_cl#2#ed_op#/SUP#ed_cl#+x-6)dx  | #ed_op#SUB#ed_cl#-3#ed_op#/SUB#ed_cl##ed_op#SUP#ed_cl#2#ed_op#/SUP#ed_cl##ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#=-(x#ed_op#SUP#ed_cl#3#ed_op#/SUP#ed_cl#/3+x#ed_op#SUP#ed_cl#2#ed_op#/SUP#ed_cl#/2-6x) | #ed_op#SUB#ed_cl#-3#ed_op#/SUB#ed_cl##ed_op#SUP#ed_cl#2#ed_op#/SUP#ed_cl##ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#=-(8/3+4/2-12)+(-27/3+9/2+18)#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#=21+1/6#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl# #ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#不知對不對#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#如有錯請指教#ed_op#/DIV#ed_cl#