Question

二次函数的配方法 y=ax的平方+bx+c

二次函数配方法的具体步骤

Answer 1

y=ax^2 + bx + c
=a(x^2 + (b/a) *x +c/a)
=a(x^2 + (b/a)*x + (b/2a)^2 - (b/2a)^2 + c/a)
=a[(x+b/2a)^2 + (4ac-b^2)/4a^2]
=a(x+b/2a)^2 + (4ac-b^2)/4a

Answer 2

y=ax方+bx+c
=ax²+bx+c
=x²+bx/a+c/a
=x²+bx/a+(b/2a)²-b²/4a²+c/a
=(x+b/2a)²-b²/4a²+4ac/4a²
=(x+b/2a)²-(b²-4ac)/4a²
=(x+b/2a)²-[√(b²-4ac)/2a]²
=[x+b/2a+√(b²-4ac)/2a][x+b/2a-√(b²-4ac)/2a]