The root formula of unary quadratic equation is derived by collocation method, so the detailed process of deriving the root formula from AX 2+BX+C (the basic form of unary quadratic equation) is as follows.
1, ax 2+bx+c = 0 (a ≠ 0, 2 stands for square), and two sides of the equation are divided by a to get x 2+bx/a+c/a = 0.
2. The shifted term is x 2+bx/a =-c/a, and both sides of the equation are added with the square of half the coefficient of the first term b/a, that is, both sides of the equation are added with b 2/4a 2.
3. The formula X 2+BX/A+B 2/4A 2 = B 2/4A 2-C/A, that is, (X+B/2A) 2 = (B 2-4AC)/4A.
4. X+B/2A = [√ (b 2-4ac)]/2A (√ stands for the number of roots) can be obtained after finding the roots, and finally X = [-b √ (b 2-4ac)]/2A can be obtained.
The Root Formula of the First and Second Equation
1、
2. Description of the formula: the form of the unary quadratic equation: ax2+bx+c=0(a≠0, A, B and C are constants).
3. Meet the conditions:
(1) is an integral equation, that is, both sides of the equal sign are algebraic expressions, if there is a denominator in the equation; And the unknown is on the denominator, then this equation is a fractional equation, not a quadratic equation. If there is a root sign in the equation and the unknown is within the root sign, then the equation is not a quadratic equation (it is an irrational number equation).
(2) contains only one unknown number.
(3) The maximum number of unknowns is 2.