证明下列不等式

2025-04-30 10:31:46
推荐回答(1个)
回答1:

f(x) = 1+xln(x+√(1+x^2)) -√(1+x^2)
f'(x)
= ln(x+√(1+x^2)) + [x/(x+√(1+x^2))] [ 1 + x/√(1+x^2) ] - x/√(1+x^2)
=ln(x+√(1+x^2)) + x/√(1+x^2) - x/√(1+x^2)
=ln(x+√(1+x^2))
> ln1
=0
min f(x) = f(0) = 1-1 =0
f(x) >0
1+xln(x+√(1+x^2)) > √(1+x^2)