Math Problem Statement

the value of p for the equation (p+6)x^2 + (p+3)x + 1 =0 has equal roots is

Solution

To find the value of pp for which the quadratic equation (p+6)x2+(p+3)x+1=0(p+6)x^2 + (p+3)x + 1 = 0 has equal roots, we use the condition for equal roots of a quadratic equation, which is when the discriminant (Δ\Delta) is zero.

For a general quadratic equation ax2+bx+c=0ax^2 + bx + c = 0, the discriminant is given by:

Δ=b24ac\Delta = b^2 - 4ac

Here, we have:

  • a=p+6a = p+6
  • b=p+3b = p+3
  • c=1c = 1

Now, apply these values to the discriminant formula:

Δ=(p+3)24(p+6)(1)\Delta = (p+3)^2 - 4(p+6)(1)

Setting Δ=0\Delta = 0 for equal roots:

(p+3)24(p+6)=0(p+3)^2 - 4(p+6) = 0

Expanding both terms:

(p+3)2=p2+6p+9(p+3)^2 = p^2 + 6p + 9 4(p+6)=4p+244(p+6) = 4p + 24

Substituting these into the equation:

p2+6p+94p24=0p^2 + 6p + 9 - 4p - 24 = 0

Simplify:

p2+2p15=0p^2 + 2p - 15 = 0

Now, solve this quadratic equation:

p2+2p15=0p^2 + 2p - 15 = 0

Factoring the equation:

(p+5)(p3)=0(p + 5)(p - 3) = 0

Thus, the solutions are:

p=5orp=3p = -5 \quad \text{or} \quad p = 3

So, the values of pp for which the quadratic equation has equal roots are p=5p = -5 or p=3p = 3.

Would you like further explanation or additional details on this? Here are some related questions to explore:

  1. What are the properties of the discriminant for quadratic equations?
  2. How do we determine if a quadratic equation has distinct, real, or complex roots?
  3. Can you explain the process of factoring a quadratic equation?
  4. What is the geometric interpretation of equal roots for a parabola?
  5. How does the discriminant affect the nature of roots?

Tip: Always check the discriminant first when solving quadratic equations to know the nature of the roots.

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Math Problem Analysis

Mathematical Concepts

Algebra
Quadratic Equations
Discriminant
Factoring

Formulas

Discriminant formula: Δ = b^2 - 4ac
Quadratic equation formula: ax^2 + bx + c = 0
Factoring quadratic equations

Theorems

The Discriminant Theorem for Equal Roots

Suitable Grade Level

Grades 10-12