What is the symmetry axis of the image with the function y = 3sin (2x-45 °) + 1? WHY?

What is the symmetry axis of the image with the function y = 3sin (2x-45 °) + 1? WHY?

The axis of symmetry of sine function is sin (x + b) = + (-) 1
So the axis of symmetry of the image of the function y = 3sin (2x-45 °) + 1 is
2x-45°=90°+K·180°
x=135°+K·180°/2