SOLUTION: Can someone help me with this problem? THANK YOU! Find all solutions in [0,2pi).Answer in the exact form. 5.7cosx+4=1.15

Algebra ->  Trigonometry-basics -> SOLUTION: Can someone help me with this problem? THANK YOU! Find all solutions in [0,2pi).Answer in the exact form. 5.7cosx+4=1.15      Log On


   

Question 1076455: Can someone help me with this problem? THANK YOU!
Find all solutions in [0,2pi).Answer in the exact form.
5.7cosx+4=1.15
Answer by ikleyn(52898) About Me  (Show Source):
You can put this solution on YOUR website!
,
5.7cos(x) + 4 = 1.15   --->

5.7*cos(x) = 1.15 - 4 --->

5.7*cos(x) = -2.85   --->

cos(x) = %28-2.85%29%2F5.7   --->

cos(x) = -1%2F2  --->

x = 2pi%2F3    and/or   x = 4pi%2F3.