高一数学题~~~~~

2024-11-15 06:01:34
推荐回答(2个)
回答1:

1.X(X-Y)-Y(X-Y)=(X-Y)方≥0 又X不等于Y所以(X-Y)方>0
所以X(X-Y)>Y(X-Y)
2.(3A+1)(A+1)-2(A+1)平方+3=3A方+4A+1-2A方-4A-2+3=A方+2
A方≥0 所以A方+2>0 (3A+1)(A+1)≥2(A+1)平方-3

3.(T+1)(T-5)-(T-2)方=T方-4T-5-T方+4T-4=-9
所以(T+1)≤(T-2)平方

回答2:

(1)X(X-Y)-Y(X-Y)化简后为X^2-2XY+Y^2=(X-Y)^2>0 所以X(X-Y)>Y(X-Y)
(2)(3A+1)(A+1)与2(A+1)平方-3 看不懂,-3是干吗的
(3)(T+1)(T-5)-(T-2)^2=-9 所以(T-2)平方>(T+1)(T-5)