Hello, Kolbeck10!

The problem is strangely worded . . .

I'm not sure exactly how we should construct the proofs.

I have the task of constructing a proof that:

. . [1] sin(x/2) = ± sqrt[(1 - cos x)/2]

. . [2] cos(x/2) = ± sqrt[(1 + cos x)/2]

I've been given the hint that it would involve the fact that:

. . (a) sin x .= .± sqrt[(1 - cos2x)/2] .and

. . (b) cos2x .= .1 - 2sin²x

They actuallygaveus hint (a) ??

Just replacexwithx/2

. . and we have: .sin(x/2) .= .± sqrt[(1 - cos x)/2] . . . . wow, that was hard!

I don't know why they gave us hint (b).

. . It's thesameas hint (a).