Independent term in \((x^p+a/x^q)^n\) for JEE

Formula

\[\text{Constant term exists when }pn-(p+q)r=0\;\Rightarrow\; r=\frac{pn}{p+q}\]

Variables: \(r\) is the binomial term parameter.

Conditions: Constant term exists only if \(\frac{pn}{p+q}\) is an integer in \([0,n]\).

Determining independent term in mixed-power expansions.