[SOLVED] how to know difference equation is linear or causal

[engwas]

hi
How can i know the difference equation is linear or non-linear and is causal or anti-causal
for example: y=x+[0.3y(n-1))^n]
thanks in advance

 

[barry]

You're missing a parenthesis.

This is causal because it doesn't depend on future values.
It's nonlinear because it's got an exponent.

Say hi to your professor for me, and tell him to give you a zero because you didn't do the required reading.

 

[engwas]

Thanks for replay
just want to confirm my information with trust textbook or from pro engineer or teacher, i am not a student to tell me professor
I know that system not linear if exponent or have sin or cos and want to get more information about linear
about causal system also
y(n-1)
y(n+1)

Thanks again for your nice reply