If for every real number

MATHEMATICS · Single correct · AP · AP Precalculus · Polynomial and Rational Functions · Polynomial and Rational Functions

Problem

f(x)=\frac{x^2-1}{x^2+1}

for every real number

x

, then the minimum value of

f

is: (1) Does not exist because

f

is bounded (2) Is not attained even though

f

is bounded (3) Is equal to

+1

(4) Is equal to

-1