SOLUTION: 3sinx-3cosx=1

Algebra.Com
Question 930586: 3sinx-3cosx=1
Answer by Alan3354(69443)   (Show Source): You can put this solution on YOUR website!
3sinx-3cosx=1
sin - cos = 1/3
sin - sqrt(1 - sin^2) = 1/3
- sqrt(1 - sin^2) = 1/3 - sin
1 - sin^2 = 1/9 - 2sin/3 + sin^2
2sin^2 - 2sin/3 - 8/9 = 0
Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc)
Quadratic equation (in our case ) has the following solutons:



For these solutions to exist, the discriminant should not be a negative number.

First, we need to compute the discriminant : .

Discriminant d=7.55555555555556 is greater than zero. That means that there are two solutions: .




Quadratic expression can be factored:

Again, the answer is: 0.853850937602944, -0.52051760426961. Here's your graph:

=======================
sin(x) =~ 0.853851
x = 1.02334 radians (the principal value)
sin(x) =~ -0.52052
x = 5.7357 radians




RELATED QUESTIONS

If 3cosx-4sinx=5,then... (answered by ikleyn)
find all solutions to... (answered by Fombitz)
Please solve 1+3Sinx=0 Thank... (answered by stanbon)
I need to prove that (2sinx+3cosx)^2 + (3sinx-2cosx)^2 = 13 work would be appreciated.... (answered by richard1234)
how to solve for x if... (answered by Greenfinch,jsmallt9)
how to solve... (answered by vasumathi)
Verify the... (answered by lwsshak3)
solve this plzz: sin^2xcosx-1=0 &... (answered by stanbon)
please help me solve this equation cosx + sqrt 3sinx = -1 (answered by Alan3354,greenestamps)