Help With Establishing an Identity: sin(@ + 2pi) = sin(@)

[Adalia]

Hello, and thank you any/all that read and respond to this.

I've been stuck on an "establishing the identity" problem for a while now, and I just can't seem to crack it. This area of Calculus is a particular weak point for me.

The problem is: Establish the identity sin(θ + 2π) = sinθ.

I have considered using the identity of sin2θ = 2sinθcosθ (simply replacing the theta with pi), but: A. I don't see how that would help at all, and B. I don't think that it's possible to simply replace the theta with a pi like that.

I honestly don't know how to solve this problem.

 

[stapel]

Establish the identity sin(θ + 2π) = sinθ.

I have considered using the identity of sin2θ = 2sinθcosθ (simply replacing the theta with pi)

You cannot do a general proof if you use a specific value for the variable. Instead, try using the identities you've memorized, such as angle-sum identities. (here)

 

[Adalia]

You cannot do a general proof if you use a specific value for the variable. Instead, try using the identities you've memorized, such as angle-sum identities. (here)

Oh, duh! Thank you so much! I feel like such a goof now!