If the derivative of \(\dfrac{e^{3x} + e^x}{e^{4x} - e^{2x} + 1}\)if
f(ex - e-x) + C, then f(x) is equal to:
1
tan-1 x
2
tan x
3
cos-1 x
4
sin x
If the derivative of \(\dfrac{e^{3x} + e^x}{e^{4x} - e^{2x} + 1}\)if
f(ex - e-x) + C, then f(x) is equal to: