# trig

posted by .

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) ?

no, its as i wrote it.

then it's got me stymied, I must be missing something rather obvious, sorry!

thanks for trying!

2cos^2x+3sinx=0
2-2sin^2x + 3 sinx=0
sin^2 x - 3/2 sin x - 1=0

quadratic equation..

sinx= (3/2 +-sqrt(9/4 +4) /2
sinx= 3/4 +- 5/4

sin x= -1/2 works.

check me.

thank you!

## Respond to this Question

 First Name School Subject Your Answer

## Similar Questions

1. ### trig

find the exact solutions (¦È in degrees) sin^2¦È+2cos¦È=-2 range= 0¡Ü¦È<360¡ã see the other problem, same procedure.
2. ### help, bobpursely

Please take a look at DEVON's trig equation at 9:14 I must be missing something obvious. If the second had been 3sin 2x it would be a straight forward question. The way it stands I was able to "reduce" it to the equation 8sin^4 x - …
3. ### Vector Calculus

Hello...i had a question. I would really appreciate it if someone could help me...tnx in advance! K my question is Find the T(t) , N(t), B(t) for r(t)=<2sint,2cost,t>; t=pie/4 ...which are normal vectors, binomial vector and …
4. ### 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 = …
5. ### trig

2sin(x)cos(x)+cos(x)=0 I'm looking for exact value solutions in [0, 3π] So I need to find general solutions to solve the equation. But do I eliminate cos(x), like this... 2sin(x)cos(x)+cos(x)=0 2sin(x)cos(x)= -cos(x) 2sin(x) = …
6. ### math

the problem is 2cos^2x + sinx-1=0 the directions are to "use an identity to solve each equation on the interval [0,2pi). This is what i've done so far: 2cos^2x+sinx-1=0 2cos^2x-1+sinx=0 cos2x + sinx =0 1 - 2sin^2x + sinx = 0 -2sin^2x+sinx-1=0 …
7. ### trig

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

how can i find all the exact solutions to the equation : 2cos^2x + 3sinx = 3 the solutions have to be between [0,2pi)
9. ### equations trig

2cos^2x-3sinx=0
10. ### Pre-Calculus

Solve the equation on the interval [0,2pi). 2sin^2x-3sinx+1=0 (2sinx+1)(sinx+1) I don't think I did the factoring correctly. When I multiply it out to double check I get 2sin^2x+3sinx+1

More Similar Questions