Posted by **Jake** on Wednesday, January 25, 2012 at 10:06pm.

How many solutions does the equation cosx + 1/2 = 1 have for 0<x<2pi

cosx+1/2=1

cosx+1=2

cosx=2-1

cosx=1

therefore 1 solution?

A) 1

b) 2

c) 3

d) 4

- Math -
**Reiny**, Wednesday, January 25, 2012 at 10:54pm
What did you do ????

cosx + 1/2 = 1

cosx = 1/2

the cosine is positive in quads I and IV

x = 30° or x = 330° or (π/6 and 11π/6)

so obviously 2 solutions between 0 and 2π

- Math -
**Jake**, Wednesday, January 25, 2012 at 11:08pm
How come I am not suppose to get rid of the the denominator?

- Math -
**Reiny**, Thursday, January 26, 2012 at 8:30am
if you had multiplied by 2 then your second line should have been

2cosx + 1 = 2 . and then

2cosx = 1

cosx = 1/2 , now pick it up in my solution.

you forgot to multiply the cosx by 2

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