How to calculate Schottky rectifier diode Power? (STP2L40U)

[TSU.11]

Hi I use STPS2L40U in the buck-boost circuit. ​

I read STP2L40U datasheet. It shows Schottky rectifier diode P=0.22xIF(AV)+ 0.06xIF(RMS) 2.

I have three question.

1. What are 0.22 and 0.06 meaning?
2. Does IF(RMS) mean LX path current or others?
3. P means power and unit is watt. ​In this equation right side, the unit is amp and amp square not watt. Is the equation correct?

I found other document(AN604) which shows how to calculate conduction loss. The equation is difference with ​STPS2L40U datasheet. Which way is correct?

I know how to calculate Table 2, but I don't know why Vt0(Tj)=0.487 - 951.358 ×10 ⋅Tj and RD(Tj ) = 13.802 ×10-3+12.839 ×10 ⋅Tj.

Where the 0.487 and 13.802 come from?