SOLUTION: Solve for x on the interval [0,2pi]. 2sin^2(x)-sin(x)=1 Someone please help, this assignment is due tomorrow and I cannot find how to do this anywhere.

Algebra ->  Trigonometry-basics -> SOLUTION: Solve for x on the interval [0,2pi]. 2sin^2(x)-sin(x)=1 Someone please help, this assignment is due tomorrow and I cannot find how to do this anywhere.       Log On


   



Question 1043023: Solve for x on the interval [0,2pi].

2sin^2(x)-sin(x)=1


Someone please help, this assignment is due tomorrow and I cannot find how to do this anywhere.

Answer by ikleyn(52884) About Me  (Show Source):
You can put this solution on YOUR website!
.
Solve for x on the interval [0,2pi].

2sin^2(x)-sin(x)=1

Someone please help, this assignment is due tomorrow and I cannot find how to do this anywhere.
~~~~~~~~~~~~~~~~~~~~~~~~~~~

2sin%5E2%28x%29-sin%28x%29 = 1.  --->

2sin%5E2%28x%29-sin%28x%29+-+1 = 0,

Factor the left side:

(2sin(x)+1)*(sin(x)-1) = 0.


Now the original equation deploys in two separate independent equations 


1.  2sin(x)+1 = 0  --->  sin(x) = -1%2F2  --->  x = 5pi%2F4  and/or  x = 7pi%2F4.


2.  sin(x) - 1 = 0  --->  sin(x) = 1  --->  x = pi%2F2.


Answer.  x = pi%2F2,  5pi%2F4,  x = 7pi%2F4.

See the lessons in this site
    - Solving simple problems on trigonometric equations
    - Solving more complicated problems on trigonometric equations
    - Solving advanced problems on trigonometric equations

They teach you by examples on how to solve similar and other trigonometric equations.