If #(x,y)# is are the coordinates of a point in the rectangular coordinate system then we convert it into polar form as follows.
Let the polar form of #(x,y)# be #(r,theta)#. Where #r# is the principal square root of sum of squares of the coordinates of the point in rectangular system i.e #r=sqrt(x^2+y^2)# and #theta# is the inverse tangent of the ratio from y coordinate to x coordinate in the rectangular coordinate system i.e #theta=tan^-1(y/x)#.
Here #x=5.7# and #y=-1.2#.
#implies r=sqrt((5.7)^2+(-1.2)^2)=sqrt(32.49+1.44)=sqrt33.93#
Also, #theta=tan^-1(-1.2/5.7)=tan^-1(-12/57)=tan^-1(-4/19)#.
Hence the polar form of the given number is #(sqrt33.93,tan^-1(-4/19))#.
