Hello Guest!
How do you solve cos(x) / sin(x)=2cos(x)
cos(x) / sin(x) = 2 cos(x) [ / cos(x)
1 / sin(x) = 2 [ reciprocal
sin(x) = 0.5
x = arcsin(0.5)
x = 30° 90° 150°
Put to the test:
cos(30°) / sin(30°) = 2 cos(30°)
0.866 / 0.5 = 2 * 0.866
cos(90°) / sin(90°) = 2 cos(90°)
0 / 1 = 2 * 0
cos(150°) / sin(150°) = 2 cos(150°)
(-0866) / 0.5 = 2 *(-0.866)
Greeting asinus :- )
!
We need to be careful about "dropping a solution" when solving this kind of problem.
Dividing away cos x will eliminate possible solutions........
We have
cosx / sinx = 2cosx rearrange as
2cosx - cosx / sin x = 0 factor out cos x
cosx ( 2 - 1/sinx) = 0
cos x ( 2 - csc x ) = 0 set both factors to 0
cos x = 0 and this happens at pi/2 + n * pi where n i s an integer
2 - csc x = 0
2 = csc x this is the same as ....... 1/2 = sin x
And this happens at pi/6 + n* 2pi and at 5pi/6 + n *2pi where n is an integer