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izharulhaq78
![\frac{1}{4}sin52,5.sin7,5 \\ \frac{1}{4}[\frac{1}{2}\{-cos(52,5+7,5)+cos(52,5-7,5)\}] \\ \frac{1}{4}[\frac{1}{2}\{-cos60+cos45\}] \\ \frac{1}{4}[\frac{1}{2}\{-\frac{1}{2}+ \frac{1}{2}\sqrt{2}\}] \\ \frac{1}{4}[\frac{1}{2}\{\frac{1}{2}\sqrt{2}-\frac{1}{2}\}] \\ \frac{1}{4}[\frac{1}{4}\sqrt{2}-\frac{1}{4}] \\\frac{1}{16}\sqrt{2}-\frac{1}{16} \\ \frac{1}{16}(\sqrt{2}-1)](https://tex.z-dn.net/?f=+%5Cfrac%7B1%7D%7B4%7Dsin52%2C5.sin7%2C5+%5C%5C++%5Cfrac%7B1%7D%7B4%7D%5B%5Cfrac%7B1%7D%7B2%7D%5C%7B-cos%2852%2C5%2B7%2C5%29%2Bcos%2852%2C5-7%2C5%29%5C%7D%5D+%5C%5C+%5Cfrac%7B1%7D%7B4%7D%5B%5Cfrac%7B1%7D%7B2%7D%5C%7B-cos60%2Bcos45%5C%7D%5D+%5C%5C+%5Cfrac%7B1%7D%7B4%7D%5B%5Cfrac%7B1%7D%7B2%7D%5C%7B-%5Cfrac%7B1%7D%7B2%7D%2B+%5Cfrac%7B1%7D%7B2%7D%5Csqrt%7B2%7D%5C%7D%5D+%5C%5C+%5Cfrac%7B1%7D%7B4%7D%5B%5Cfrac%7B1%7D%7B2%7D%5C%7B%5Cfrac%7B1%7D%7B2%7D%5Csqrt%7B2%7D-%5Cfrac%7B1%7D%7B2%7D%5C%7D%5D+%5C%5C+%5Cfrac%7B1%7D%7B4%7D%5B%5Cfrac%7B1%7D%7B4%7D%5Csqrt%7B2%7D-%5Cfrac%7B1%7D%7B4%7D%5D+%5C%5C%5Cfrac%7B1%7D%7B16%7D%5Csqrt%7B2%7D-%5Cfrac%7B1%7D%7B16%7D+%5C%5C+%5Cfrac%7B1%7D%7B16%7D%28%5Csqrt%7B2%7D-1%29 "\frac{1}{4}sin52,5.sin7,5 \\ \frac{1}{4}[\frac{1}{2}\{-cos(52,5+7,5)+cos(52,5-7,5)\}] \\ \frac{1}{4}[\frac{1}{2}\{-cos60+cos45\}] \\ \frac{1}{4}[\frac{1}{2}\{-\frac{1}{2}+ \frac{1}{2}\sqrt{2}\}] \\ \frac{1}{4}[\frac{1}{2}\{\frac{1}{2}\sqrt{2}-\frac{1}{2}\}] \\ \frac{1}{4}[\frac{1}{4}\sqrt{2}-\frac{1}{4}] \\\frac{1}{16}\sqrt{2}-\frac{1}{16} \\ \frac{1}{16}(\sqrt{2}-1)")
8 votes
Thanks 11
winegh
kenapa di kali 1/2 ?
izharulhaq78
karena rumus awalnya itu 2sinAsinB = -cos(A+B)+cos(A-B), karena hanya ada sinAsinB maka : sinAsinB=1/2[-cos(A+B)+cos(A-B)]
winegh
kalo misalkan ditanya 4sinAsinB rumusnya gmn?
izharulhaq78
4sinAsinB = 2 × 2sinAsinB = 2 × [-cos(A+B)+cos(A-B)]
winegh
oiyaiya saya ngerti makasih yaaa :)
hendrisyafa
Jika -2 sin a .sin b = cos (a+b)- cos (a-b) Maka Sin a. Sin b = - 1/2 { cos (a+b)- cos (a-b)} Sehingga 1/4 sin a. Sin b = 1/4 (-1/2 { cos (a+b)-cos (a-b)} = -1/8 { cos (a+b)-cos (a-b)} = -1/8 { cos 60 - cos 45} = -1/8 { 1/2 - 1/2 √2 } = 1/16 (√2 - 1)
3 votes
Thanks 4
winegh
yang aku bingung min nya bisa pindah gt gmnka?
hendrisyafa
dipindah kan ke ruas kanan. disesuaikan dgn soal.
winegh
yg http://brainly.co.id/tugas/2586097 sm yg http://brainly.co.id/tugas/2586109 tolong dibantu ka. makasih :) maaf ngerepotin kaa