Question #52f58

1 Answer
Nov 23, 2017

cos^2 3x+3sin3x=3

=>1-sin^2 3x+3sin3x=3

=>sin^2 3x-3sin3x+2=0

=>sin^2 3x-2sin3x-sin3x+2=0

=>sin3x(sin3x-2)-(sin3x-2)=0

=>(sin3x-2)(sin3x-1)=0

sin3x=2->"not possible"

So sin3x=1=sin(pi/2)

=>3x=npi+(-1)^npi/2" where "ninZZ

=>x=(npi)/3+(-1)^npi/6" where "ninZZ