can anyone put some light on my concepts of even and odd function and how to identify its graph?? plz reply asap…

can anyone put some light on my concepts of even and odd function and how to identify its graph?? plz reply asap...

say y = f(x) is a function of x

if y = f(-x) i.e. if v change -x instead of x and still the value of function remains unchanged, then the function is even function

for eg. cos(x) = cos(-x)

on the other hand, if y = -f(-x) then it is odd function i.e. value of function changes by sign alone when independent variable changes by sign

for eg. sin(-x) = -sin(x)

Can anyone please provide me good material of functions(concepts n practice questions )

plz help me...