求PREP-PS-1-33 解

jesuisdesole

33.   4484-!-item-!-187;#058&004004

If x^4 + y^4 = 100, then the greatest possible value of x is between

 

(A) 0 and 3

(B) 3 and 6

(C) 6 and 9

(D) 9 and 12

(E) 12 and 15

ＡＮＳ：Ｂ

hopefaith001

x最大，那么Y最小的时候是Y=0,此时X^4=100=>X^2=10,根据3^2=9,即可推出答案B. 应该是大于3而小于6的。