SOLUTION: Hello I really need help for this question,so if you guys can help I will be really appreciated. The question is I have to use a double-angle identity to find the exact value of co

Question 967167: Hello I really need help for this question,so if you guys can help I will be really appreciated. The question is I have to use a double-angle identity to find the exact value of cos x =12/13 and it said 0 degree I don't get how this thing (0
Answer by tenkun(12) (Show Source): You can put this solution on YOUR website!
cos x =12/13
Sin^2x= 1- cos^2x
. = 1- 144/169
= 169/169 -144/169
= 25/169
Sin x= √25/169
= 5/13
Sin 2x = 2*sin x * cos x
= 2 * 5/13 * 12/13
= 120/169
RELATED QUESTIONS
Hello tutors! I am extremely confused on this question it would be extremely appreciated... (answered by Theo)

I know these questions are easy for you guys but I just don't retain any algebra at all.... (answered by jim_thompson5910)

Hello I have been confused on unit multipliers from the beginning and then the teacher... (answered by solver91311)

Hello tutor, i really need help with this math problem solving question. Help would be... (answered by sudhanshu_kmr)

I really need some help - my assignment is due tomorrow night and I have about 6 more... (answered by scott8148)

Hi! I really need your help with this question! A school gives each student a password (answered by ikleyn)

Hi I have included the problem for some reason I cannot attach the picture but If you can (answered by Theo)

Hi tutor, i really need help with this question. Im a really hard worker, and ive been... (answered by nerdybill)

Hello, I have a question I need help with. Your time is appreciated. A = 1/2bh; for h... (answered by Alan3354)