Simplify x^(n-1)⋅³√(y^2/2x^5) into Rationalised Surd Form

In summary, to simplify an expression like x^(n-1)⋅³√(y^2/2x^5) into rationalised surd form, we can use the rules of exponents and surds to rewrite and simplify the terms. The purpose of rationalising surds is to make expressions involving radicals easier to work with. However, not all expressions can be simplified into rationalised surd form. While rationalising surds is not always necessary in mathematical calculations, it is commonly used when dealing with radicals or solving certain equations. Other methods for simplifying expressions into rationalised surd form include using the conjugate method or manipulating the expression to eliminate radicals, but the first method described is the most commonly
  • #1
Bill_Nye_Fan
31
2

Homework Statement


Q7.[/B] a) Express [itex]x[/itex]^[itex](n-1)⋅³√(y^2/2x^5) [/itex] in its simplest, rationalised surd form.
b) Given that the solution to part a) is 5, and that [itex]y[/itex] can be expressed as [itex]1/x[/itex]^[itex](6n+5)/4)[/itex], determine the value of [itex]x[/itex]. Again, express your answer in rationalised surd form.

*Note, this is a non-calculator question*

Homework Equations


None, but I suppose knowledge of the index laws would be needed.

The Attempt at a Solution


I have attached my attempted workings to the sheet. While I believe to have gotten to a reasonable answer, I have no way of checking if I am right (this question has come from a sheet, not a textbook). This is by far the hardest problem I've encountered with in dices thus far, so I would be very grateful if anybody could double check my work. Thank you for your time.
 

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  • #2
You can plug your results in calculators like WolframAlpha to check them.
I don't see obvious mistakes but checking the result with a computer is easier. Some steps look unnecessary.

Edit: Oh, didn't check where the thread was.
 
Last edited:
  • #3
Bill_Nye_Fan said:

Homework Statement


Q7.[/B] a) Express [itex]x[/itex]^[itex](n-1)⋅³√(y^2/2x^5) [/itex] in its simplest, rationalised surd form.
b) Given that the solution to part a) is 5, and that [itex]y[/itex] can be expressed as [itex]1/x[/itex]^[itex](6n+5)/4)[/itex], determine the value of [itex]x[/itex]. Again, express your answer in rationalised surd form.

*Note, this is a non-calculator question*

You've posted a math problem in the Intro Physics HW forum, but I've moved to the Pre-Calculus HW forum, where it's a better fit.

In the future, please try to post your HW questions in the appropriate HW forum by subject.
 

1. How do I simplify the expression x^(n-1)⋅³√(y^2/2x^5) into rationalised surd form?

To simplify this expression, we need to use the rules of exponents and surds. First, we can rewrite x^(n-1) as x^n/x. Then, we can simplify the cube root of (y^2/2x^5) by breaking it down into separate cube roots and simplifying the numerator and denominator. Finally, we can combine the simplified terms to get the expression in rationalised surd form.

2. What is the purpose of rationalising surds?

The purpose of rationalising surds is to simplify expressions involving radicals and make them easier to work with. This allows us to solve equations and perform operations more efficiently.

3. Can we always simplify an expression into rationalised surd form?

No, not all expressions can be simplified into rationalised surd form. Some expressions may have irrational numbers that cannot be simplified further.

4. Is rationalising surds necessary in all mathematical calculations?

No, rationalising surds is not always necessary in mathematical calculations. It is only necessary when dealing with expressions involving radicals or when solving certain types of equations.

5. Are there any other methods for simplifying expressions into rationalised surd form?

Yes, there are other methods for simplifying expressions into rationalised surd form, such as using the conjugate method or manipulating the expression to eliminate radicals. However, the method described in the first question is the most commonly used and efficient method.

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