Question

Can anyone help me with this proof using trig identities?

Answer 1

Perhaps

Answer 2

How can I help?

Answer 3

@DannyO19

Answer 4

"cis" is quite unusual in trig. What does "cis" mean to you? We'll have to agree on terms.

Answer 5

cis means cos theta+ i sin theta

Answer 6

thank you.

Answer 7

do u need a proof like LHS=RHS

Answer 8

I think so @ayeshaafzal221

Answer 9

Oh that's interesting, \[cis = \cos \theta + i \sin \theta\] I did not know that. This is Euler's identity, \[e^{i \theta} = \cos \theta + i \sin \theta \] you may need to apply this.

Answer 10

\(\text{cis}(\theta) = \cos (\theta) + i \sin (\theta)\)

is a common notation. I'm surprised that it seems new to people