How do you determine the resistors R1 and R2
for a desired output voltage
V_{out}?

Suppose you want an output voltage
**V _{out} = 5 V**.
For this you use the

V_{out} =
1.25 × (1 + ^{R2}/_{R1})
+ (0.00005 × R2)

As the the resistor **R1** you
usually choose a resistance in the range of
several **hundred Ω**.
Hence **R1 = 220 Ω**
is a good choice.

Now you can use this in the **formula**, and you get...

R2 = (V_{out} - 1.25) / 0.00573

Since you want an output voltage
**V _{out} = 5 V**...

R2 = 655 Ω

In the next experiment you look
again at the **heat generation** of the voltage regulator...