推 freePrester : PA^2 + PB^2 = (x-1)^2 + y^2 + (x+1)^2 + y^2 10/18 11:04
推 wayne2011 : 設參數x=3+2cost,y=4+2sint,可得Max=100,Min=20 10/18 11:04
→ freePrester : = 2(x^2 + y^2) + 2 10/18 11:04
→ freePrester : 所以求到原點的距離平方 * 2 + 2 的極值即可 10/18 11:05
→ freePrester : 到原點最小值 = 3 、最大值 = 7 10/18 11:07
→ freePrester : 得 M = 100 , m = 20 10/18 11:07
→ nokol : 懂了,感謝兩位大師指點~謝謝你們~ 10/18 12:58