x? -x+ 1+2m? +2mx
=x? +(2m- 1)x+(2m? + 1)
=[x+(2m- 1)/2]? +2m? + 1-[(2m- 1)/2)?
=[x+(2m- 1)/2]? +m? +m+3/4
∵m? +m+3/4=(m+ 1/2)? + 1/2 >0
∴[x+(2m- 1)/2]^2+m^2+m+3/4>; 0
∴x? -x+ 1+2m? +2mx & gt; 0
∴x? -x+ 1 & gt; -2m? -2mx
2. Prove:
( 1)
∫a+b+c = 0 a > b > c
∴a>; 0 degrees celsius & lt0 b-c>;; 0
∴ab-ac=a(b-c)>; 0
Namely AB-AC > 0
∴ab>ac
(2)
∫a+b+c = 0 a > b > c
∴a>; 0 degrees Celsius-LT0 means that A is positive and C is negative.
(1) if b≥0, the minimum value of b is 0, and the maximum value is infinitely close to a, so that 0 = 0/a ≤ b/a.
2 if b
The maximum value of b is infinitely close to 0, when b/a
So I got a B.
To sum up, the range of b/a is:-1/2.
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