In the new coordinate system origin is shifted to (h,k) and the axes are rotated through angle of 90∘ in the anti-clockwise direction. The new co-ordinates of (x,y) is obtained by the following method.
1) (x + iy) becomes (x + iy) e−iπ2
Let it be (x+iy) or (x,y)
2)(x,y) becomes (x - h,y - k)