SOLUTION: Please help me solve this question: Find all solutions for 2/3Sin^2-cosx=1 on the interval (0,2pi)

Algebra.Com
Question 1056628: Please help me solve this question: Find all solutions for 2/3Sin^2-cosx=1 on the interval (0,2pi)
Found 2 solutions by Alan3354, stanbon:
Answer by Alan3354(69443)   (Show Source): You can put this solution on YOUR website!
Please help me solve this question: Find all solutions for 2/3Sin^2-cosx=1 on the interval (0,2pi)
-----------
What do you need help with?

Answer by stanbon(75887)   (Show Source): You can put this solution on YOUR website!
Find all solutions for (2/3)Sin^2-cosx=1 on the interval (0,2pi)
--------------------------
(2/3)(1-cos^2(x)) - cos(x) = 1
-------
(2/3) - (2/3)cos^2(x) - cos(x) = 1
---------------------------------------
2 - 2cos^2(x) - 3cos(x) = 3
------------------------------------------
2cos^2(x) + 3cos(x) + 1 = 0
--------------------------------------
(2cos(x) + 1)(cos(x)+1) = 0
----
cos(x) = -1/2 Or cos(x) = -1
-------------------------------------
x = (2/3)pi or x = (4/3)pi or x = pi
----------------------
Cheers,
Stan H.
--------------------------------

RELATED QUESTIONS

I need help finding the solutions for this question. Find all solutions in the interval... (answered by lwsshak3)
could you help me find all the solutions in the interval [0, 2pi)... (answered by lwsshak3)
Please help me solve this problem: Find the solutions on the interval [0,2pi).... (answered by tinbar)
find all solutions: 3sin^2x+2sinx-1=0; in the interval... (answered by ikleyn)
Can someone please help me with my questions please m practicing for exams thanks! (John... (answered by solver91311)
could you help me find all the solutions in the interval [0, 2pi)... (answered by lwsshak3)
Please help me find all solutions of the equation in the interval [0, 2pi) 2 sin^2x + 3... (answered by lwsshak3)
Solve cos^2(w)=-3sin(w) for all solutions 0 <= w <... (answered by lwsshak3)
[(Sqrt2) secx-2](2sinx+1)=0 Find all solutions for this equation with the interval [0,... (answered by lwsshak3)