Unlocking Trig Identities: Proving sin(2x + pi/3)

In summary, using trig identities and double angle formulas, the attempted solution for showing that sin(2x + pi/3) = sin(2x) + sin(2(x+pi/3)) involved using the identity for sin(a+b) and breaking down the left hand side into two parts, ultimately leading to the use of the identity sin(a)-sin(b) = 2 cos((a+b)/2) sin((a-b)/2).
  • #1
iamthegelo
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0

Homework Statement



By using trig formulas show that,

sin(2x + pi/3) = sin(2x) + sin(2(x+pi/3))

Homework Equations



Trig Identities

The Attempt at a Solution



I've used double angle formulas, sin(a+b) formulas, I just can't seem to get it.
 
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  • #2
It does look like a case for sin(a + b). Can you show us what went wrong when you simply apply the identity for sin(a + b) = sin(a) ... + ... to sin(2x + pi/3) ?
 
  • #3
write (for the left hand side)
sin(2x + pi/3)=[sin(2x + pi/3)-sin(2x +2pi/3)]+sin(2(x + pi/3))
recall the identity for
sin(a)-sin(b)
 

Related to Unlocking Trig Identities: Proving sin(2x + pi/3)

What are trigonometric identities?

Trigonometric identities are equations that involve trigonometric functions and are true for all values of the variables involved. They are used to simplify complex expressions and solve equations involving trigonometric functions.

What is the purpose of proving sin(2x + pi/3)?

The purpose of proving sin(2x + pi/3) is to demonstrate the validity of a trigonometric identity. By using mathematical manipulations and substitution, we can show that the left side of the equation is equal to the right side, thereby proving its truth.

What are the steps for proving sin(2x + pi/3)?

The steps for proving sin(2x + pi/3) are:

  1. Start with the left side of the equation and use algebraic manipulations to simplify it.
  2. Apply trigonometric identities, such as the double angle formula, to further simplify the expression.
  3. Substitute values for the variables involved, such as substituting 2x for x in sin(x).
  4. Use properties of trigonometric functions, such as the periodicity property, to transform the expression into a simpler form.
  5. Continue simplifying until the left side of the equation is equal to the right side.
  6. Conclude that the trigonometric identity is proven to be true.

Why is it important to understand trigonometric identities?

Understanding trigonometric identities is important because they are used in many areas of mathematics, physics, and engineering. They allow us to simplify complex expressions and solve equations involving trigonometric functions, making it easier to find solutions to real-world problems.

Can trigonometric identities be used in real-life applications?

Yes, trigonometric identities have many real-life applications. They are used in fields such as engineering, physics, navigation, and astronomy to solve problems involving angles and distances. They are also used in signal processing, computer graphics, and other fields that involve waves and oscillations.

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