Math Problem Statement

Find the value of a^4 + b^4 + c^4 given the system of equations: a + b + c = 4, a^2 + b^2 + c^2 = 10, and a^3 + b^3 + c^3 = 22.

Solution

The image presents the following system of equations involving three variables aa, bb, and cc:

a + b + c = 4 \tag{1} a^2 + b^2 + c^2 = 10 \tag{2} a^3 + b^3 + c^3 = 22 \tag{3}

You are asked to find the value of:

a4+b4+c4=?a^4 + b^4 + c^4 = ?

Step-by-step Solution:

1. Use the identity for sums of squares:

From Equation (1): (a+b+c)2=a2+b2+c2+2(ab+bc+ca)(a + b + c)^2 = a^2 + b^2 + c^2 + 2(ab + bc + ca) Substitute the known values from (1) and (2): 42=10+2(ab+bc+ca)4^2 = 10 + 2(ab + bc + ca) 16=10+2(ab+bc+ca)16 = 10 + 2(ab + bc + ca) 6=2(ab+bc+ca)6 = 2(ab + bc + ca) ab + bc + ca = 3 \tag{4}

2. Use the identity for sums of cubes:

Using the identity: a3+b3+c33abc=(a+b+c)(a2+b2+c2abbcca)a^3 + b^3 + c^3 - 3abc = (a + b + c)(a^2 + b^2 + c^2 - ab - bc - ca) Substitute the known values from (1), (2), and (4): 223abc=4(103)22 - 3abc = 4(10 - 3) 223abc=4×722 - 3abc = 4 \times 7 223abc=2822 - 3abc = 28 3abc=6-3abc = 6 abc = -2 \tag{5}

3. Calculate a4+b4+c4a^4 + b^4 + c^4:

Now, to find a4+b4+c4a^4 + b^4 + c^4, use the identity: a4+b4+c4=(a2+b2+c2)22(a2b2+b2c2+c2a2)a^4 + b^4 + c^4 = (a^2 + b^2 + c^2)^2 - 2(a^2b^2 + b^2c^2 + c^2a^2) We already know a2+b2+c2=10a^2 + b^2 + c^2 = 10, so: a4+b4+c4=1022(a2b2+b2c2+c2a2)a^4 + b^4 + c^4 = 10^2 - 2(a^2b^2 + b^2c^2 + c^2a^2) To find a2b2+b2c2+c2a2a^2b^2 + b^2c^2 + c^2a^2, we use: (ab+bc+ca)2=a2b2+b2c2+c2a2+2abc(a+b+c)(ab + bc + ca)^2 = a^2b^2 + b^2c^2 + c^2a^2 + 2abc(a + b + c) Substitute from (4) and (5): 32=a2b2+b2c2+c2a2+2(2)(4)3^2 = a^2b^2 + b^2c^2 + c^2a^2 + 2(-2)(4) 9=a2b2+b2c2+c2a2169 = a^2b^2 + b^2c^2 + c^2a^2 - 16 a2b2+b2c2+c2a2=25a^2b^2 + b^2c^2 + c^2a^2 = 25

Now substitute back: a4+b4+c4=1002×25a^4 + b^4 + c^4 = 100 - 2 \times 25 a4+b4+c4=10050a^4 + b^4 + c^4 = 100 - 50 a4+b4+c4=50a^4 + b^4 + c^4 = 50

Final Answer:

a4+b4+c4=50a^4 + b^4 + c^4 = 50

Would you like more details on any step or have any questions?

Here are five follow-up questions:

  1. Can you apply a similar method to calculate higher powers of a5+b5+c5a^5 + b^5 + c^5?
  2. How can the symmetric nature of equations help simplify calculations in other contexts?
  3. What is the importance of identities like sums of squares and cubes in algebraic problems?
  4. Can we generalize this approach for larger systems with more variables?
  5. How would the problem change if one of the values of aa, bb, or cc was known?

Tip: Identifying symmetry in equations often simplifies the problem-solving process by reducing the number of variables or steps required.

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Math Problem Analysis

Mathematical Concepts

Algebra
Power Sums
Symmetric Polynomials

Formulas

(a + b + c)^2 = a^2 + b^2 + c^2 + 2(ab + bc + ca)
a^3 + b^3 + c^3 - 3abc = (a + b + c)(a^2 + b^2 + c^2 - ab - bc - ca)
a^4 + b^4 + c^4 = (a^2 + b^2 + c^2)^2 - 2(a^2b^2 + b^2c^2 + c^2a^2)

Theorems

Power Sum Formulas
Symmetric Polynomial Identities

Suitable Grade Level

Grade 10-12