# equations trig

posted by LiNnda

2cos^2x-3sinx=0

1. Reiny

2(1 - sin^2x) - 3sinx = 0
-2sin^2x - 3sinx + 2 = 0
2sin^2x + 3sinx - 2 = 0
(2sinx -1)(sinx + 2) = 0
sinx = 1/2 or sinx = -2
x = 30° or 150° or (sinx = -2 has no solution)

x = 30 or 150 ° which is also π/6 or 5π/6 radians

## Similar Questions

1. ### trig

find the exact solutions 2cos^2x+3sinx=0 the way it stands, that is a "nasty" question. Are you sure the second term isn't 2sin(2x) ?
2. ### Math - Solving Trig Equations

Solve each equation for 0 is less than and equal to "x" is less than and equal to 360 3sinx = 2cos^{2}x ----- I don't know how to solve this equation...this is what I have, but I don't know if I'm on the right track or not 3sinx = …
3. ### Math - Solving Trig Equations

What am I doing wrong? Equation: sin2x = 2cos2x Answers: 90 and 270 .... My Work: 2sin(x)cos(x) = 2cos(2x) sin(x) cos(x) = cos(2x) sin(x) cos(x) = 2cos^2(x) - 1 cos(x) (+/-)\sqrt{1 - cos^2(x)} = 2cos^2(x) - 1 cos^2(x)(1 - cos^2(x))
4. ### trig

What is the shift along x of the following trig functions?
5. ### trig

how can i find all the exact solutions to the equation : 2cos^2x + 3sinx = 3 the solutions have to be between [0,2pi)
6. ### 10th grade math help

How do you solve? 3-3sinx-2cos^2(x) = 0
7. ### trig

find the general solutions to the equations: 1) sec x = -2 2) 2 sin^2 x = 1 3) cos^2 x - 2cos x + 1 = 0
8. ### trig

Find minimum value of 2cos x + 2cos y
9. ### trig

Find minimum value of 2cos x + 2cos y
10. ### trig

Find minimum value of 2cos x + 2cos y

More Similar Questions