Question

Help here please:

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

a. a. sin^2(75°

Answer 1

you know cos2A = ??

Answer 2

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

Answer 3

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

Answer 4

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

Answer 5

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

Answer 6

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

Answer 7

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

Answer 8

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

Answer 9

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

Answer 10

like that?