Conics Algebra Help! (1 Viewer)

[lookoutastroboy]

Hey,

There's a conics Q (number 7) in Terry Lee where I dont understand one step of algebra to the next - (pg 332) - how'd they factorise the (a^2 + b^2) bit?






Cheers,
L.A.

 

[K4M1N3]

havent looked at TL but either
a^2 + b^2
= a^2 + 2ab + b^2 - 2ab
= (a+b)^2 -2ab (or (a-b)^2 +2ab)

elsewise: a^2 + b^2
= a^2 - (-b^2)
= (a+ib)(a-ib)

 

[AAEldar]

Haven't looked at TL but either:


Elsewise:

Fixed it up with Latex.

 

[K4M1N3]

Fixed it up with Latex.

Ta for that, i get lazy XD

 

[Herbert Braun]

it might be an e substitution, i.e the expression for b^2 or a^2 = for that particular conic slice