What is the Sum of the Reciprocals of Variables in Solving Cubic Root Equations?

In summary, the problem involves three equations with variables a, b, and c. By substituting the equations, it can be simplified to a + b + c = 0. Solving for the given expression, 1/a + 1/b + 1/c, involves replacing a + b + c with 0 in the equations and solving for the variables.
  • #1
wendy<3
1
0
Hi, can you help me with this problem?

[itex]a = \sqrt[3]{1 - 4b - 4c}[/itex]
[itex]b = \sqrt[3]{1 - 4c - 4a}[/itex]
[itex]c = \sqrt[3]{1 - 4a - 4b}[/itex]

Find [itex]\dfrac{1}{a} + \dfrac{1}{b} + \dfrac{1}{c}[/itex]

Thanks
 
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  • #2
a^3 = 1 -4b -4c
b^3 = 1- 4c -4a
c^3 = 1- 4a -4b
=> a^3 +4b +4c = b^3 +4c +4a = c^3 +4a + 4b
<=> a^3 + 4b + 4c = b^3 + 4c + 4a and a^3 + 4b + 4c = c^3 +4a +4b
<=> a+b+c = 0 ( I have ignored the conditions a =b or a =c since they are easy)
it should be easy by replacing a + b + c = 0 into those first equations
 
Last edited:

1. What is a cubic root equation?

A cubic root equation is an algebraic equation that involves finding the value of a variable when it is raised to the third power. It can be written in the form of ax^3 + bx^2 + cx + d = 0, where a, b, c, and d are constants and x is the variable.

2. How do you solve a cubic root equation?

To solve a cubic root equation, you can use various methods such as the factorization method, the substitution method, or the Cardano's formula. These methods involve manipulating the equation to isolate the variable and then using algebraic techniques to find its value.

3. What is the importance of solving cubic root equations?

Solving cubic root equations is important in many fields, including engineering, physics, and economics. It allows us to find the roots or solutions of equations, which represent the values of variables that satisfy the equation. This is crucial in understanding and analyzing real-world problems and making informed decisions.

4. What are the possible types of solutions for cubic root equations?

A cubic root equation can have three types of solutions: real, complex, or imaginary. Real solutions are the values of the variable that satisfy the equation and can be represented on a number line. Complex solutions involve the use of imaginary numbers and cannot be represented on a number line. Imaginary solutions are not real solutions and do not satisfy the equation.

5. Can all cubic root equations be solved?

Yes, all cubic root equations can be solved using the methods mentioned above. However, some equations may have complex or imaginary solutions, which may not always be relevant or useful in the given context. In such cases, the real solutions are the ones that are typically considered.

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