Can someone tell me what are these equations ??

Question

lastdaywork · Answer

The topic is - Properties of Triangles
IDK what p, q, r denote...or is this just a shorthand notation ?

lastdaywork · Answer

BTW, the book is 
IIT Mathematics by M L Khanna & J N Sharma

amistre64 · Answer

the sum of stuff ...

lastdaywork · Answer

I was wondering why would anyone put such an obvious thing b/w serious formulas..

amistre64 · Answer

i assume pqr is defined elsewhere in the chapter?  :)

lastdaywork · Answer

That's the problem..I don't have any theory book (for this topic)..this one only has formulas and questions..

lastdaywork · Answer

@random231 Any idea ??

random231 · Answer

where on earth did p r q come from?

random231 · Answer

might b a mispint?

random231 · Answer

i havnt seen this formula lemme check my books once!!

lastdaywork · Answer

I checked Arihant 33 Years IIT Papers..found the same set of identities,  without any explanation..

random231 · Answer

nope i dont hav it in my fiitjee materials or any books.....

random231 · Answer

they seem to be using completely different notions!!

random231 · Answer

some things are extra get a teacher and he'll tell u wether to ignore that!

lastdaywork · Answer

That's the problem..the equations are too obvious to be considered extra..
Maybe it's just a short-hand they defined..

Thanks for you time :)

random231 · Answer

no problem!!!

amistre64 · Answer

whats on page 448?

amistre64 · Answer

and if there is an answer key, find one that references #12 :)