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Lingqin is pure A B+C
Original formula 0 Therefore, the original formula contains the factor (b+c-a) because the original form is symmetrical.
The original form contains the equation (a+c-b), (b+a-c), so a 2 (b + c) + b 2 (a + c) + c 2 (a + b) -a 3-b 3-c 3-2abc k(a + b-c) (b + c -a) (c + a -b).
Let a=b=c=1
k 1 so.
a^2(b+c)+b^2(a+c)+c^2(a+b)-a^3-b^3-c^3-2abc=-(a+b-c)(b+c-a)(c+a-b)
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Order a b+c
Original 0 So the original contains the factor (b+c-a).
Since the original form is symmetrical.
The original style with a beat punch has a factored stool (a+c-b), (b+a-c), so. a^2(b+c)+b^2(a+c)+c^2(a+b)-a^3-b^3-c^3-2abc=k(a+b-c)(b+c-a)(c+a-b)
Let a=b=c=1
k 1 so.
A 2(b+c)+b 2(a+c)+c 2(a+b)-a 3-b 3-c 3-2abc attack Zheng J (a+b-c)(b+c-a)(c+a-b).
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A classic factorization provides an idea: take the last two formulas apart and make up (b-c) original formula = a 2(b-c) + (b 2)c-(c 2)b + a(c 2)-a(b 2).
a^2(b-c)+bc(b-c)-a(b+c)(b-c)=(b-c)[(a^2)-ab-ac+bc]=(b-c)(a-b)(a-c)
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Method 1: Let a b x, a c y, b c z, then:
Original. =z(c+x)(b+y)-y(a+z)(c-x)+x(b-y)(a-z)
z(bc+bx+cy+xy)-y(ac-ax+cz-xz)+x(ab-ay-bz+yz)
bcz+bxz+cyz+xyz-acy+axy-cyz+xyz+abx-axy-bxz+xyz
3xyz+bcz-acy+abx
3(a-b)(a-c)(b-c)+bc(b-c)-ac(a-c)+ab(a-b)
3(a-b)(a-c)(b-c)+bc(b-c)-a^2c+ac^2+a^2b-ab^2
3(a-b)(a-c)(b-c)+bc(b-c)+a^2(b-c)-a(b^2-c^2)
3(a-b)(a-c)(b-c)+bc(b-c)+(b-c)[a^2-a(b+c)]
3(a-b)(a-c)(b-c)+(b-c)(bc+a^2-ab-ac)
3(a-b)(a-c)(b-c)+(b-c)[-c(a-b)+a(a-b)]
3(a-b)(a-c)(b-c)+(b-c)(a-b)(a-c)
4(a-b)(a-c)(b-c)。
Method 2: It is easy to verify that when a b, the original formula is 0;When a c, the original 0;When b c, the original formula is 0, and it is known from the remainder theorem that the original formula contains the equation (a b)(a c)(b c).
It is clear that the original is cubic and (a b)(a c)(b c) is cubic and the original k(a b)(a c)(b c) where k is a constant to be determined.
Let a 0, b 1, c 1, get:
k(a b)(a c)(b c) k(0 1)(0 1)(1 1) 2k,(b c)(a b c)(a b c) (1 1)(0 1 1)(0 1 1) 8,(c a)(b c a)(b c a) (1 0)(1 1 0)(1 1 0) 0,(a b)(c a b)( c a b) (0 1) ( 1 0 1) (1 0 1) 0, in this case 8, k 4.
So: 4(a b)(a c)(b c).
a^2b+b^2c+c^2a-ab^2-bc^2-ca^2a^2(b-c)+a(c^2-b^2)+bc(b-c)a^2(b-c)-(ab+ac)(b-c)+bc(b-c)(b-c)(a^2-ac-ab+bc) >>>More
The original form can be reduced to:
1/(ab+c-1)+1/(bc+a-1)+1/(ca+b-1) >>>More
Because in the triangle ABC, ab=2, bc=2 times the root number 3, AC=4, the triangle abc is a right-angled open-angle, right-angled angle B (because ab 2 >>>More
Root number B - root number A +8 > A - root number ab + "root number B B - root number ab - root number a a + root number ab> divided by 8 root number ab root number a + root number b = ( b - a + 8) a ( a - b) + [ 8 ( b - a) - 8 ( a + b)]*a+ b) 8 ab = ( b - a + 8) a ( a - b) + 8 a ( b- a ( b- a) (
The first thing to consider is the special triangle. Because (a b 0), it can be determined that a +b is the largest edge, i.e., the hypotenuse. Therefore, it can be predicted that the sum of the squares of the two right-angled sides of a right-angled triangle is equal to the square of the hypotenuse. >>>More