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anonymous
 one year ago
Find an exact value.
cos 165°
anonymous
 one year ago
Find an exact value. cos 165°

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Nnesha
 one year ago
Best ResponseYou've already chosen the best response.1whats two number you can add to get 165? and those two number suppose to be on the unit circle

Nnesha
 one year ago
Best ResponseYou've already chosen the best response.1then use formula \[\large\rm cos(a+b)=\cos a \times \cos b  \sin a \times \sin b\]

Nnesha
 one year ago
Best ResponseYou've already chosen the best response.1well 75 is not on the unit circle :/

Nnesha
 one year ago
Best ResponseYou've already chosen the best response.130+135 40+120 22560 for this u have to use cos(ab)=cos a times cos b + sin a times sin b

Nnesha
 one year ago
Best ResponseYou've already chosen the best response.1so \[\huge\rm cos(45+120)=\cos 45 \cos 120  \sin 45 \sin 120\]

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0okay, i see. what do i do from there?

Nnesha
 one year ago
Best ResponseYou've already chosen the best response.1so \[\large\rm cos(45+120)=\cos 45 \cos 120  \sin 45 \sin 120\] now use the unit circle cor exact value of cos and sin cos 45 =? cos 120 =? sin 45=? sin 120 =? plugin their exact values

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0cos 45 = (radical)2 / 2 cos 120 = 1/2 sin 45 = (radical) 2 /2 sin 120 = (radical) 3 /2 is that right?

Nnesha
 one year ago
Best ResponseYou've already chosen the best response.1\[\frac{ \sqrt{2} }{ 2 } \times \frac{ 1 }{ 2 }  \frac{ \sqrt{2} }{ 2 } \times \frac{ \sqrt{3} }{ 2}\] solve
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