How do you solve sinxcosx-2cosx=0sinxcosx2cosx=0?

1 Answer
Aug 4, 2016

x in {pi/2+kpi, k in ZZ}

Explanation:

sin(x) cos(x) - 2cos(x)=0

rarr color(red)(cos(x)) * color(blue)(""(sin(x)-2)) = 0

rarr color(red)(cos(x)=0) color(white)("XXX")"or"color(white)("XXX") color(blue)(sin(x)-2=0

rarr color(red)(x=pi/2+k * pi)" or "color(white)("XX")color(blue)(sin(x)=2

color(white)("XXXXXXXXXXXXXXXX")color(blue)("impossible since " sin in [-1,+1]