Help here please:

Find the exact value of the following, show all work:

a. a. sin^2(75°

Question

Help here please:

Find the exact value of the following, show all work:

a.	a. sin^2(75°

experimentx · Answer

you know cos2A = ??

anonymous · Answer

cos (30) = sqrt(3)/2 that?

experimentx · Answer

5:30 am here ... actually i was planning to sleep.

experimentx · Answer

$$\cos(2A) = (cosA)^2 - (sinA)^2$$
$$\cos(2A) = 1 -2 (sinA)^2$$
$$1- cos(2A) = 2(sinA)^2$$
$$(1- cos(2A))/2 = (sinA)^2$$

anonymous · Answer

Oh. Im so sorry! I didnt know! ok then, I will ask for help elsewhere, Thanks for your help today! Good night:)!

experimentx · Answer

I will stay for a while ...
sin^2(75) = (1-cos150)/2

anonymous · Answer

Oh ok:) so I can find the exact value by applying the formula you provided from above?

anonymous · Answer

is the problem just to find sin^2(75) ?

anonymous · Answer

Its actually, sin^2(75°) / sin 45° cos^2 30°

anonymous · Answer

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like that?