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## Find all solutions in the interval [0, 2π). cos2x + 2 cos x + 1 = 0?

So I got this wrong on a quiz.

Could you please solve this problem step-by-step please?

I know I factor this equation. So I got (cosx+1)^2 = 0

So when I look on the unit circle, how do I know which is the solution according to the interval?

On the practice problems, I got all of the solutions however, the answers in the back of the book didn’t include some of the solutions. How does the interval work? I thought the interval provided such as this one here is supposed to include the whole unit circle.

Find all solutions in the interval [0, 2π). cos2x + 2 cos – ok its kinda complicated yet receives somewhat only on the top sinxcos2x+cosxsin2x=0 we going to be using the sin^2x +cos^2=a million alot cos2x=sin^2 – cos^2 and sin2x=2sinxcosx sinx(sin^2x – cos^2x) + cosx(2sinxcosx)=0 sinx(sin^2x-a million+sin^2x)+2sinxcos^2x=0 2sin^3x-sinx+2sinx(a million-sin^2x)= 2sin^3x-sinx+2sinx-2sin^3x=0 sinx=0 note how the sines cancel one yet another out and fromSolve the equation 2cos2x = √3 for 0°≤x≤360° I did this: cos2x = √3 /2 2x=30 x=15 x=15, 165, 195, 345 Is this correct? Solve the equation √3 sin2x + cos2x = 0 for -π≤x≤π No idea how to approach this one Thanks a . math. Find all solutions to the equation tan(t)=1/tan (t) in the interval 0You can put this solution on YOUR website! Find all solutions to the equation. cos2x + 2 cos x + 1 = 0 (2cos^2-1) + 2cos + 1 = 0 2cos^2 + 2cos = 0 (cos)(2cos+2) = 0 cos(x) = 0 or cos(x) = -1

find all solutions of the equation 2sin x cos2x-cos2x=0 – How to solve: Solve on the interval [0, 2π). cos x – sin x cos x = 0. By signing up, you'll get thousands of step-by-step solutions to your…Number of solutions of [math]\sin(2x) + \cos(2x) + \sin(4x) = 2, \ x \in [-\pi,\pi][/math] Let's study what happens to the LHS for different sub-intervals of [mathGet an answer for '`cos(2x) – cos(x) = 0` Find the exact solutions of the equation in the interval [0, 2pi).' and find homework help for other Math questions at eNotes

SOLUTION: Find all solutions to the equation. cos2x + 2 – Solve for ? cos(x)=-1/2. Take the inverse cosine of both sides of the equation to extract from inside the cosine. The exact value of is . The cosine function is negative in the second and third quadrants. To find the second solution, subtract the reference angle from to find the solution in the third quadrant. Simplify .2 + cos 2x = 3 cos x. use identity that cos 2x = 2cos^2 x – 1. sub to give: 2 + (2cos^2 x – 1) – 3 cos x = 0. 2cos^2 x – 3cos x + 1 = 0 (2cos x – 1)(cos x – 1) = 0Use a comma Solve 6 tan x sin x-6 tan x=0 in the interval [0,21). T The solution(s) is/are 0,21,21 2 (Use a comma to separate answers as needed. Type exact answers, using a as needed.) Find all solutions in the interval [0,2x). sin 2x cos X+ Sin x=0 1 37 71 55 X=10. 4 4 4 4 (Type an exact answer, using a as needed.