Solve Quadratic Question Urgently: Find Value of p

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Discussion Overview

The discussion revolves around solving a quadratic equation of the form x² + 2px + (3p + 4) = 0, where p is a positive constant. Participants are attempting to find the value of p that results in equal roots for the equation.

Discussion Character

  • Homework-related
  • Mathematical reasoning
  • Debate/contested

Main Points Raised

  • One participant asserts that the condition for equal roots leads to the equation (2p)² - 4(1)(3p + 4) = 0, simplifying to 4(p+1)(p-4) = 0, suggesting p = 16.
  • Another participant questions how the value of 16 was derived, indicating that there are two values of p that satisfy the condition.
  • A different participant confirms finding p = 4, but expresses confusion about the factor of 4 outside the brackets affecting the solution.
  • One participant clarifies that dividing both sides by 4 leads to p = 4, while retaining the factor of 4 results in 4p - 16 = 0, also yielding p = 4.
  • A later reply acknowledges a mistake in their earlier reasoning and expresses relief at the simplicity of the correct answer.

Areas of Agreement / Disagreement

Participants generally agree that p = 4 is a solution, but there is contention regarding the derivation of p = 16 and the implications of the factor of 4 in the equation.

Contextual Notes

There is ambiguity regarding the treatment of the factor of 4 in the quadratic equation, and the discussion does not resolve whether both values of p are valid under the given conditions.

Who May Find This Useful

Readers interested in quadratic equations, particularly those involving conditions for equal roots and the implications of constants in algebraic expressions.

thomas49th
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Quadratic Question [Urgent]

The equation [tex]x^{2} + 2px + (3p + 4) = 0[/tex], where p is a postitve constant, has equal roots

Q) Find the value of p

Well if it has equal roots b² - 4ac = 0
so

(2p)² - 4(1)(3p + 4) = 0

4p² - 12p - 16 = 0

4(p² - 3p - 4) = 0

4((p+1)(p-4)) = 0

so the anwser is p = 16

BUT the question booklet says p = 4

Which is right?
Thx :)
 
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How did you get 16? Also there are two values of p that make the statement true.
 
yeh i know the there are 2 valeus but p is a positive constant, as it says in the question

erm i got p = 4
but then u get the 4 otside the brackets so i multiply p by 4 giving me p = 16 or do you not count the four outside the brackets?
 
Well, you can either divide both sides by 4 first to get p = 4 or if you wanted to keep the 4.
4(p-4) =0
4p-16 = 0
p = 4
 
that was a stupid mistake on my part
sorry
yeh it was soooo simple

thanks
:)
 

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