if the absolute term in the expansion of (root x -k/x2)10is 405 ,then k is equal to - Maths - Binomial Theorem

Question

if the absolute term in the expansion of (root x
-k/x2)10is 405 ,then k is equal to??

Anuradha Sharma · Accepted Answer

For the given series, Tr+1=10Crx10-r-kx2r=10Cr×x5-5r2-krFor this to be independent of x , r must be 2 
 So that10C2k2=40545k2=405k = ±3

if the absolute term in the expansion of (root x -k/x2)10is 405 ,then k is equal to??