HP 33s - Manual (Page 75)

Real–Number Functions 4–11
Example: Polar to Rectangular Conversion.
In the following right triangles, find sides x and y in the triangle on the left, and
hypotenuse r and angle
θ
in the triangle on the right.
y
10
30
o
x
r
4
3
θ
Keys: Display: Description:
Ÿ {}  Sets Degrees mode.
30 ‘ 10 | s
)
 Calculates x.
[
)
 Displays y.
4 ‘ 3 { r
)
 Calculates hypotenuse (r).
[
)
 Displays θ .
Example: Conversion with Vectors.
Engineer P.C. Bord has determined that in the RC circuit shown, the total
impedance is 77.8 ohms and voltage lags current by 36.5º. What are the values
of resistance R and capacitive reactance X
C
in the circuit?
Use a vector diagram as shown, with impedance equal to the polar magnitude, r,
and voltage lag equal to the angle,
θ
, in degrees. When the values are converted
to rectangular coordinates, the x–value yields R, in ohms; the y–value yields X
C
, in
ohms.