BITSAT 2023 · Paper 2 · Mathematics · Application of Derivatives
The function f(x)= (1+x)-(2 x)/(2+x) is increasing on
The function f(x)=log(1+x)−2+x2x is increasing on
Options
A(0,∞)
B(−∞,0)
C(−∞,∞)
D None of these
Correct answer
A. (0,∞)
Step-by-step solution
Given f(x)=log(1+x)−2+x2xf′(x)=1+x1−(2+x)2(2+x)(2)−2x=1+x1−(2+x)24=(1+x)(2+x)2(2+x)2−4−4x=(1+x)(2+x)2x2>0 for all x∈(0,∞)$Thus,givenfunction\mathrm{f}(\mathrm{x})isincreasingon(0,\infty)$.