please help me, cal expert

[tinhnho]

Find equivalent expressions( shortest is best) for the following do not involce any trig function or w or T. Thanks
EX: sin(n*pi) =0 for all n and cos(n*pi)=(-1)^n for all n


a) cos((2n+1)*pi/2) where n is a positive integer

b) sin((2n+1)*w*T/2) where n is a positive integer

c) cos(n*w*T/2) where n is a positive integer

d) sin(2n+1)*pi/2) - cos(2n*pi/2) where n is a positive integer


p/s: w is omega

[tinhnho]

i got a) =0

any one know how to get b and c ? thanks

[ewmayer]

I thought the whole point of homework was to figure it out for yourself...

I thought the whole point of this forum is to help people with math homework?

[akruppa]

What are w and T? If those are just indeterminates, I think there's not much you can do to simplify b) and c).

Alex

[R.D. Silverman]

Originally Posted by akruppa

What are w and T? If those are just indeterminates, I think there's not much you can do to simplify b) and c).

Alex

I believe that his post said that w = omega, for which I will assume he means
the first cardinal infinity. Now, since the domain of sin() and cos() is
the real numbers and omega is not a real number, it makes the expression(s)
gibberish.

[philmoore]

Originally Posted by Unregistered

I thought the whole point of this forum is to help people with math homework?

The title of the thread would certainly lead people to assume that. Perhaps that was not what the moderator intended?

[R.D. Silverman]

Originally Posted by Unregistered

I thought the whole point of this forum is to help people with math homework?

It is. But "help with homework" does not equal "do my homework for me".
To get help, you first need to show what you have done already with each
of the problems. Then we can guide you.

[alpertron]

w = 2*pi*f = 2*pi/T so it should be easy to continue from here. But I think this help is too late for him since he posted his questions in 2005.

[davieddy]

Originally Posted by Unregistered

I thought the whole point of this forum is to help people with math homework?

Sounds like he is still interested. The dates explain why I have not
noticed this post before.

[akruppa]

Or it was someone else wondering about Ernst's response. In fact, I think the Homework Help forum was formed after 2005, and this old thread moved there.

Alex