ddxtan-11-cosx1+cosx=
12
0
1
-12
Explanation for correct option:
Step-1: Simplify the given data.
Given, ddxtan-11-cosx1+cosx
=ddxtan-12sin2x22cos2x2=ddxtan-1tanx2=ddxx2
Step-2: Differentiate w.r.t x
=12×1
=12
Hence, correct answer is option A
loge(n+1)−loge(n−1)=4a[(1n)+(13n3)+(15n5)+...∞] Find 8a.