Verifying Identity: sinX(1-2cos^2x+cos^4x)=sin^5x

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In summary, the equation given is an identity and can be proven by working with one side to show it is equal to the other, or by simplifying both sides to get identical expressions. The left side can be written as sin(x)(1 - cos^2(x))^2.
  • #1
louie3006
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Homework Statement


sinX(1-2cos^2x+cos^4x)=sin^5x
 
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  • #2
On the left hand side of the equation, you have sinX and on the right sinx.

Is this capitalisation deliberate, or accidental.

Assuming it's accidental, your first step would be to divide both sides by sinx.

This gives

1 - 2cos^2x + cos^4x = sin^4x.

Can you do anything with that?

Clue: Can the left hand side be factorised??
 
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  • #3
louie3006 said:

Homework Statement


sinX(1-2cos^2x+cos^4x)=sin^5x
Assuming that you need to prove that this is an identity, you can work with one side to show that it is equal to the other side, or work with each side separately to get to expressions that are identical.

The left side is sin(x) (1 - cos^2(x))^2 [Parentheses would be very helpful in your original equation.]
 

Related to Verifying Identity: sinX(1-2cos^2x+cos^4x)=sin^5x

1. What is the purpose of verifying identity in mathematics?

The purpose of verifying identity in mathematics is to prove that two expressions are equivalent. This is important because it allows us to simplify complicated expressions and solve equations more easily.

2. How do I verify the identity sinX(1-2cos^2x+cos^4x)=sin^5x?

To verify this identity, you can use trigonometric identities such as the Pythagorean identity and the double angle formula. You can also use algebraic manipulation and substitution to transform one side of the equation into the other.

3. Can I use a calculator to verify this identity?

While a calculator can be helpful in checking your work, it is not recommended to solely rely on a calculator for verifying identities. It is important to understand the concepts and techniques used in verifying identities in order to have a deeper understanding of the mathematics involved.

4. Are there any tips for verifying identities more efficiently?

One tip for verifying identities is to work with one side of the equation at a time and simplify it using known identities or algebraic techniques. Another tip is to look for patterns and similarities between the two sides of the equation, as this can lead to a more efficient solution.

5. Why is verifying identity important in real-world applications?

Verifying identity is important in real-world applications because it allows us to accurately model and solve complex problems in fields such as physics, engineering, and finance. It also helps to ensure the accuracy and reliability of mathematical models and calculations used in various industries.

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