" : If "f(x)=(x^(2)-1)/(x^(2)+1)" ,for every real number.Then what is the minimum value of "f?

If f(x)=(x^(2)-1)/(x^(2)+1). For every real number x then the minimum value of f. does not exist because f is unbounded is not attained exen through f is bounded is equal to 1 is equal to -1

If f(x)=(x^2-1)/(x^2+1) . For every real number x , then the minimum value of fdot does not exist because f is unbounded is not attained even through f is bounded is equal to 1 is equal to -1

If f(x)=(x^2-1)/(x^2+1) . For every real number x , then the minimum value of fdot does not exist because f is unbounded is not attained even through f is bounded is equal to 1 is equal to -1

If f(x)=(x^2-1)/(x^2+1) . For every real number x , then the minimum value of fdot (a) does not exist because f is unbounded (b) is not attained even through f is bounded (c) is equal to 1 (d) is equal to -1

If f(x)=(x^2-1)/(x^2+1) . For every real number x , then the minimum value of fdot (a) does not exist because f is unbounded (b) is not attained even through f is bounded (c) is equal to 1 (d) is equal to -1

If f(x) = frac {x^2 -1}{x^2 +1} , for every real x, then the minimum value of f(x) is.

If x is real number, then the minimum value of x^2+x+1 is