#2cos^2θ−3sinθ=0#
#2(1-sin^2theta)−3sinθ=0# because # cos^2θ+sin^2theta=1#
#2-2sin^2theta−3sinθ=0#
#2sin^2theta+3sinθ-2=0#
#sinθ=(-3+-sqrt(3^2-4*2*(-2)))/(2*2)#
#sinθ=(-3+-sqrt(9+16))/4#
#sinθ=(-3+-sqrt(25))/4=(-3+-5)/4#
#sin theta=-8/4 or sin theta= 2/4#
#sin theta=-2 or sin theta= 1/2#
# theta notin RR or sin theta= 1/2#
# theta= 60^o or theta= (-60^o +360^o)#
# theta= 60^o or theta= 300^o#