Solve : cos24 + cos55 + cos155 + cos204 + cos300
Answers
Answered by
1
cos24+cos55+cos155+cos204+cos300 =cos738
Answered by
2
L.H.S. = cos24+cos204+cos55 + cos155 +cos300
= cos 24 + cos (180+24) + sin (90-55) + cos (90+65) + cos (360-60) [ cos x = sin (90-x)]
= cos 24 - cos 24 + sin 35 - sin 65 + cos 60
= (cos 24 - cos 24) + (sin 35 - sin 65 )+ cos 60
= 0 - sin 30 + cos 60
= -1/2 + 1/2
= 0
Hence 0 is answer
Ansuselina:
how can you directly subtract sin35 - sin 65...?
Hello there..!!
sin(90-65)= cos 65 .....then how come cos65 - sin65 = 0
cos 65 - sin65 = sin 30 ...sry*
Similar questions