The following scientific calculator has been used: Casio fx-3800P.

Example 1

Obtain the values of θ and r when the point P is shown as x=4 and y=3 (z=4+j3) in the rectangular co-ordinates.

- “DEG” (MODE IV)
- x “SHIFT” “” y =, we find r=5
- “SHIFT” ““, we find θ=36.86 degrees

Example 2

Obtain the values of θ and r when the point P is shown as x=-10 and y=20 (z=-10+j20) in the rectangular co-ordinates.

- “DEG” (MODE IV)
- x “SHIFT” “” y =, we find r=22.36
- “SHIFT” ““, we find θ=116.56