lim x -> infinity : sqrt(x^2 + 4x(cos x) ) - x
find the limit (or lack there of)
The Attempt at a Solution
ok so i used the addition/subtraction law to show that the limit of f(x) = - x as x --> infinity = infinity
now for the other half of the function, i cant seem to find out how to mathematically prove that there is no limit. logically i can tell that there is no limit because COS X has no limit.
can someone explain how i prove this mathematically?