Condition 1: If x = 1, y = 1, z =0; sufficient to prove x^4 + y^4 > z^4. If x = 4, y = 4, z = 5; insufficient to prove x^4 + y^4 > z^4. Therefore condition 1 is insufficient.
Condition 2: If x = 1, y = 1, z = 0; sufficient to prove x^4 + y^4 > z^4. If x = 1, y = 1, z = -3; insufficient to prove x^4 + y^4 > z^4. Therefore condition 2 is in sufficient.
Combining 1 and 2: If x = 1, y = 1, z = 0; sufficient to prove x^4 + y^4 > z^4. If x = 4, y = 4, z = -5; insufficient to prove x^4 + y^4 > z^4. Therefore conditions 1 and 2 are not sufficient.
欢迎光临 国际顶尖MBA申请交流平台--TOPWAY MBA (http://forum.topway.org/)
