How to solve 3sinx + 3cosx = secx + cosecx for x? Thank you!

1 Answer
Feb 18, 2018

See the answer below...

Explanation:

=>3sinx+3cosx=secx+cscx3sinx+3cosx=secx+cscx

=>3sinx+3cosx=1/cosx+1/sinx3sinx+3cosx=1cosx+1sinx

=>3sinx+3cosx=(sinx+cosx)/(sinx cdot cosx3sinx+3cosx=sinx+cosxsinxcosx

=>(sinx+cosx)(3-1/(sinx cdot cosx))=0(sinx+cosx)(31sinxcosx)=0

=>(sinx+cosx)(3-2/(2 cdot sinx cdot cosx))=0(sinx+cosx)(322sinxcosx)=0

=>(sinx+cosx)(3-2/sin(2x))=0(sinx+cosx)(32sin(2x))=0

Either,

(sinx+cosx)=0(sinx+cosx)=0

=>sinx=-cosxsinx=cosx

=>tanx=-1=tan(-pi/4)tanx=1=tan(π4)

color(red)(ul(bar(|color(green)(=>x=npi-pi/4)|

Or,

(3-2/sin(2x))=0

=>2/sin(2x)=3

=>sin2x=2/3=sinalpha

=>2x=npi+(-1)^nalpha

=>color(red)(ul(bar(|color(green)(x=(npi)/2+(-1)^n(alpha/2))|

Hope it helps...
Thank you...