145a
sin(π/3-x/2)≥0
sin(x/2-π/3)≤0
π+2πk≤x/2-π/3≤2π+2πk
4π/3+2πk≤x/2≤7π/3+2πk
8π/3+4πk≤x≤14π/3+4πk,k∈z
145b
cos(x/3+π/4)≥0
-π/2+2πk≤x/3+π/4≤π/2+2πk
-3π/4≤x/3≤π/4+2πk
-9π/4+6ππk≤x≤3π/4+6πk,k∈z
147a
(sin²x-cos²x)(sin²x+cos²x)<5/8<br>-cos2x<5/8<br>cos2x>-5/8
π-arccos5/8+2πk<2x<-arccos5/8+2πk<br>π/2-1/2*arccos5/8+πk