Math Problem Statement

If (-1) / (√2 + 1 - √3) = (√p + √q + r) / t, where p, q, r, t are rational numbers (Q), then find (p^2 + q^2 + r^2 + t^2) / 6.

Solution

We are given the equation:

12+13=p+q+rt\frac{-1}{\sqrt{2} + 1 - \sqrt{3}} = \frac{\sqrt{p} + \sqrt{q} + r}{t} where p,q,r,tQp, q, r, t \in \mathbb{Q} (rational numbers), and we are asked to find:

p2+q2+r2+t26\frac{p^2 + q^2 + r^2 + t^2}{6}

Step 1: Simplify the Left-Hand Side

We start by simplifying the expression 12+13\frac{-1}{\sqrt{2} + 1 - \sqrt{3}}. To simplify this, we rationalize the denominator.

Multiply both numerator and denominator by 2+1+3.\text{Multiply both numerator and denominator by } \sqrt{2} + 1 + \sqrt{3}. 12+13×2+1+32+1+3=1(2+1+3)(2+1)2(3)2\frac{-1}{\sqrt{2} + 1 - \sqrt{3}} \times \frac{\sqrt{2} + 1 + \sqrt{3}}{\sqrt{2} + 1 + \sqrt{3}} = \frac{-1(\sqrt{2} + 1 + \sqrt{3})}{(\sqrt{2} + 1)^2 - (\sqrt{3})^2}

Now simplify the denominator using the difference of squares:

(2+1)2(3)2=(2+22+1)3=3+223=22(\sqrt{2} + 1)^2 - (\sqrt{3})^2 = (2 + 2\sqrt{2} + 1) - 3 = 3 + 2\sqrt{2} - 3 = 2\sqrt{2}

Thus, the expression becomes:

21322\frac{-\sqrt{2} - 1 - \sqrt{3}}{2\sqrt{2}}

Step 2: Equating with the Right-Hand Side

We now equate this expression to the right-hand side of the equation:

21322=p+q+rt\frac{-\sqrt{2} - 1 - \sqrt{3}}{2\sqrt{2}} = \frac{\sqrt{p} + \sqrt{q} + r}{t}

By comparing the terms, we see that:

  • p=2\sqrt{p} = -\sqrt{2}, so p=2p = 2
  • q=3\sqrt{q} = -\sqrt{3}, so q=3q = 3
  • r=1r = -1
  • The denominator on both sides must match, so t=22t = 2\sqrt{2}. But since tQt \in \mathbb{Q}, we rationalize it as t=2t = 2.

Step 3: Find p2+q2+r2+t26\frac{p^2 + q^2 + r^2 + t^2}{6}

Now calculate the required expression:

p2+q2+r2+t2=22+32+(1)2+22=4+9+1+4=18p^2 + q^2 + r^2 + t^2 = 2^2 + 3^2 + (-1)^2 + 2^2 = 4 + 9 + 1 + 4 = 18

Finally,

p2+q2+r2+t26=186=3\frac{p^2 + q^2 + r^2 + t^2}{6} = \frac{18}{6} = 3

Thus, the answer is:

3\boxed{3}

Let me know if you'd like any clarification or further details!

Here are 5 related questions to explore:

  1. What is the process of rationalizing complex denominators?
  2. How can we generalize this method for any quadratic radicals in the denominator?
  3. How do we equate irrational terms with rational numbers in such equations?
  4. Can this method be applied if the equation involves cube roots instead of square roots?
  5. What role do the properties of rational numbers play in this equation?

Tip: Rationalizing a denominator with multiple radicals often involves using the conjugate to simplify the expression effectively.

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Math Problem Analysis

Mathematical Concepts

Algebra
Rationalizing Denominators
Equating Expressions

Formulas

Rationalizing Denominators: Multiply by conjugate (a - b)(a + b)
Difference of squares: (a^2 - b^2)
Equation comparison: Left-hand side = Right-hand side

Theorems

Rationalization
Properties of Rational Numbers

Suitable Grade Level

Grades 10-12