Mathematica Small mathematica operator question

[FocusedWolf]

Hi,

Quick question. In the ti89 i can do this:

x+1|x=2
Answer = 3

It works like x + 1 given x = 2...do 2+1 = 3. I'm not sure what the '|' operator would be called in this case...

Anyway, is this shorthand possible in mathematica?

like if i had: yy = E^T*C[1]+C[2], and i wanted to specify C[1]=1/6... what would do it?

 

[CompuChip]

yy = E^T*C[1]+C[2] /. { C[1] -> 1/6 }
 x + y /. {x -> 2, y -> 1}

or just

yy = E^T*C[1]+C[2] /. C[1]->1/6
x+1 /. x -> 2

if you have only one replacement.

You can also do

Block[ {C[1]=1/6},
   E^T*C[1]+C[2]
 ];

if you need the expression more often, but since you assign it anyway that's not necessary here (thought I generally prefer not assign variables)

 

[FocusedWolf]

Thx that'll do