If fundamental period of f(x)=|sec4πx|+|cosec 6πx| is P, then coefficient of x−24P in the expansion (x+bx3)32P is
A
16C1b
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
16C9b9
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
12C3b3
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
16C7b7
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
Open in App
Solution
The correct option is D16C7b7 Fundamental period of f(x)=P= L.C.M. of 14 and 16 ⇒P=12
So we need to find coefficient of x−12 in (x+bx3)16
We know Tr+1=16Cr(bx3)rx16−r ⇒Tr+1=16Crbrx16−4r
Now, to get coefficient of x−12 put 16−4r=−12 ⇒r=7 ∴Required coefficient =16C7b7