.
Find solutions in the internal (0,2π)
Cos^2x+2cosx+1= 0
~~~~~~~~~~~~~~~~~~~~~~~~
= 0 ====> = 0 ====> cos(x) + 1 = 0 ====>
cos(x) = -1 ====> x = .
Answer. There is only one solution in the given interval: x = .
To see more examples of solved trigonometry equations with detailed solutions, look into the lessons
- Solving simple problems on trigonometric equations
- Solving typical problems on trigonometric equations
- Solving more complicated problems on trigonometric equations
- Solving advanced problems on trigonometric equations
in this site.
Also, you have this free of charge online textbook in ALGEBRA-II in this site
- ALGEBRA-II - YOUR ONLINE TEXTBOOK.
The referred lessons are the part of this online textbook under the topic "Trigonometry: Solved problems".