Help with Algebra 2/Trigonometry problem

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    Algebra
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Discussion Overview

The discussion revolves around the equation x = -b/2a, specifically in the context of proving its validity and understanding its significance in relation to the vertex of a parabola. The scope includes algebraic reasoning and connections to trigonometry as mentioned by the original poster.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Homework-related

Main Points Raised

  • The original poster seeks to understand how to prove the equation x = -b/2a and its relevance in finding the x-coordinate of a vertex.
  • One participant questions the need to "prove" the equation, suggesting it may be more about demonstrating its truth in a specific context.
  • Another participant mentions that using calculus, one can show that x = -b/2a is the point where a parabola reaches its minimum or maximum, indicating its role as the axis of symmetry.
  • A participant recognizes that x = -b/2a is part of the quadratic formula and connects it to the vertex of the parabola described by the equation y = ax² + bx + c.
  • There is a suggestion that the coefficients a and b can be used to determine the vertex of the parabola, indicating some confusion about the relationship between the coefficients and the vertex.

Areas of Agreement / Disagreement

Participants express varying levels of understanding regarding the equation and its proof. Some agree that x = -b/2a relates to the vertex of a parabola, while others question the need for proof and the context in which the equation is applied. The discussion remains somewhat unresolved as participants clarify their positions without reaching a consensus.

Contextual Notes

The original poster does not provide the specific problem context, which may limit the clarity of the discussion. There is also some ambiguity regarding the proof and its application to different situations.

daodude1987
I'm having trouble with proving this equation: x=-b\2a
I am not really familiar with this equation but my trigonometry teacher says it is something from Algebra 2. How can I prove why or how this equation works for finding the x-coordinate?
 
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What do you mean "prove it"? It's an equation- its sometimes true and sometimes not. I suppose you mean "prove it is true for this particular situation" but you haven't told us what the situation is.
Could you please state the entire problem exactly?
 
Using simple calculus, you can show that x=-b/2a is the point at which a parabola attains a minimum or maximum.
The vertical line x=-b/2a that goes thru this point is the axis of symmetry.
 
Ah! Thanks, Stephen, I recognized "-b/(2a)" as part of the quadratic formula but didn't recognize that he was asking for a proof that the x coordinate of the vertex of the parabola y= ax2+ bx+ c is -b/(2a).
 
wait isn't -b/2a the vertex of a parabola? i kinda of forgot this but i think you can the coeficients of b and a get the vertex of the parabola
 
Yes, that was what StephenPrivitera told you!
 
o sorry i only saw the oroginal question
 

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