-1.
4sin3x+3cos3x=5.2
{4sin3x=2.6=>{sin3x=0.6==>{3x = (-1) ^k*arcsin0.6+pi*n
{3cos3x=2.6=>{cos3x=0.8=>{3x=+-arccos0.8+2pi*n
-1.
4sin3x+3cos3x=5.2
{4sin3x=2.6=>{sin3x=0.6==>{3x = (-1) ^k*arcsin0.6+pi*n
{3cos3x=2.6=>{cos3x=0.8=>{3x=+-arccos0.8+2pi*n