Question

find the general solution sin 2x equal to root 3 cos x?​

Answer 1

Answer:

Changing sin2x into 1−cos2x; we get

2(1−cos2x)+3cosx+1=0

or 2cos2x−3cosx−3=0

∴cosx=43±3+24

=43+33=3 or 2−3

Since 3 is greater than 1 it is not admissible as cosx can not be greater than 1.

∴cosx=−3/2=−cos(π/6)

=cos(π−π/6)=cos(5π/6)

∴x=2nπ±(5π/6).