English Deutsch Français Italiano Español Português 繁體中文 Bahasa Indonesia Tiếng Việt ภาษาไทย
All categories

I don't get it.

2007-12-10 12:57:22 · 4 answers · asked by hohum 1 in Science & Mathematics Mathematics

4 answers

You don't. It is derived from the "completion of the perfect square" method of solving for roots.

2007-12-10 13:05:16 · answer #1 · answered by cattbarf 7 · 1 0

You don't. The quadratic formula is derived from the quadratic equation
ax^2 + bx + c = 0
as follows:
x^2 + (b/a)x + c/a = 0
x^2 + (b/a)x + (b/2a)^2 - (b/2a)^2 + c/a = 0
(x + b/2a)^2 - b^2/4a^2 + 4ac/4a^2 = 0
(x + b/2a)^2 - (b^2 - 4ac)/4a^2 = 0
(x + b/2a - (√(b^2 - 4ac))/2a)(x + b/2a + (√(b^2 - 4ac))/2a) = 0
(x + (b - √(b^2 - 4ac))/2a)(x + (b + √(b^2 - 4ac))/2a) = 0
x = - (b - √(b^2 - 4ac))/2a, - (b + √(b^2 - 4ac))/2a
x = - (b ± √(b^2 - 4ac))/2a
or
x = (- b ± √(b^2 - 4ac))/2a

2007-12-10 13:25:20 · answer #2 · answered by Helmut 7 · 1 0

quadratic formula cannot be derived from this as in quadratic equations u have only 2 variables but pythagoras theorem have 3 variables............

2007-12-10 13:07:51 · answer #3 · answered by vizhy 1 · 0 0

(-b + square root of b^2 - 4ac)/2a and (-b - square root of b^2 - 4ac)/2a

plug in the values and get the answers

2007-12-10 13:14:09 · answer #4 · answered by jh 2 · 0 1

fedest.com, questions and answers