I need help with the sum of cosines. Specifically this problem: Cos(2pi/3 + pi/4) Detail is highly appreciated. Thank you in advance.
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Originally Posted by Neversh I need help with the sum of cosines. Specifically this problem: Cos(2pi/3 + pi/4) Detail is highly appreciated. Thank you in advance. cos (a + b ) = cos(a)cos(b) - sin(a)sin(b) a= 2pi/3 b = pi/4 ...and you definitely know the sines and cosines of these two angles. Good luck!
Had to finish dinner. So, the awnser would be: $\displaystyle (-sqrt(2) - sqrt(6))/4$ ?
Originally Posted by Neversh Had to finish dinner. So, the awnser would be: $\displaystyle (-sqrt(2) - sqrt(6))/4$ ? correct.
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