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Mathematics problems in senior one.
1, solution: difference method

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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