Please help me with this equation.
sin x (cos x - sqrt(3)/2) = 0
You can easily tell two of the answers, which is
1. x = 0 + n * 360,
2. x = 180 + n * 360.
Now, the answer sheet contains a third answers, which says,
3. x = ± 30 + n * 360.
How can x be 30? When written in the equation the answer will be sin (30) (cos (30) - sqrt(3)/2) = 0.437 which is not zero. How can this be?
+130514 Notice that
(cos x - sqrt(3)/2) = 0 add sqrt(3)/2 to both sides
cos x = sqrt(3)/2 and this occurs at 30 degrees and at -30 degrees....or ....in general terms...
x = +/- 30 + n*360
Make sure your calculator is in degree mode....and you will find that sin(30) [ cos (30) - sqrt(3)/2 ] = 0
