Expand cos^5t in Mathematica: Guide & Steps

[Dustinsfl]

How can I tell Mathematica to expand cos^5 t?

The command expand doesn't do it.

 

[Chris L T521]

How can I tell Mathematica to expand cos^5 t?

The command expand doesn't do it.

Are you trying to write it in first degree terms of sine and cosine? If so, expand isn't the command to do this and I don't know off the top of my head if there is one that would do such a thing.

 

[Ackbach]

Is
$$\cos^{5}(t)=\frac{10\cos(t)+5\cos(3t)+\cos(5t)}{16}$$
helpful?

 

[Chris L T521]

Is
$$\cos^{5}(t)=\frac{10\cos(t)+5\cos(3t)+\cos(5t)}{16}$$
helpful?

I learned something new today; I didn't realize that this was an option in Mathematica. The command:

TrigReduce[Cos[x]^5]

outputs what Ackbach posted above.