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6 votes
Can you help me on quadratic formulas?

2 Answers

3 votes

I take it as you want to learn about the formula.

The quadratic formula is a formula where you can solve x for any quadratic equation in form ax^2+bx+c=0.

The formula is x=
(-b+-√(b^2-4ac))/(2a).

The +- means + or - for the 2 solution in each equation.

*All above information is what you need to know about the quadratic formula and solve for answer, but I will go a step further in my answer to prove the quadratic formula always work.


0=ax^2+bx+c


0=(ax+(b)/(2))^2-(b^2)/(4)+c (This step is completing the square)


(ax+(b)/(2))^2=(b^2)/(4)-c


(2ax+b)^2=b^2-4ac


2ax+b=+or-√(b^2-4ac)


2ax=-b+ or -√(b^2-4ac)


x=(-b+-√(b^2-4ac))/(2a)

This is my way of proving this formula although there are many other ways to do it too, if there is any questions, feel free to ask me in the comment :-).

User YMC
by
3.2k points
8 votes
Sure. Where is the question and I hope I can answer it

User Julissa
by
3.6k points