How do you solve 1-sinx=sqrt3cosx1sinx=3cosx?

1 Answer
Aug 11, 2016

2kpi2kπ
pi/3 + 2kpiπ3+2kπ

Explanation:

1 - sin x = sqrt3cos x1sinx=3cosx
sin x + sqrt3cos x = 1sinx+3cosx=1
Call t the arc whose tan t = sqrt3tant=3 --> t = pi/3t=π3
We get:
sin x + (sin t)/(cos t)cos x = 1sinx+sintcostcosx=1
sin x.cos (pi/3) + sin (pi/3).cos x = cos t = 1/2sinx.cos(π3)+sin(π3).cosx=cost=12
(sin x + pi/3) = 1/2(sinx+π3)=12
Trig table and unit circle give 2 solution arcs:
a. x + pi/3 = pi/3x+π3=π3 --> x = 0
b. x + pi/3 = 2pi/3x+π3=2π3 --> x = (2pi)/3 - pi/3 = pi/3x=2π3π3=π3
General answers:
x = 2kpix=2kπ
x = pi/3 + 2kpix=π3+2kπ