Which of the following function's output decreases without bound as $x$ increases without bound? $f(x)=x^{7}-x^{5}-x^{3}-9$ $f(x)=1-x^{2}$ $f(x)=1-x^{2}+x^{3}$ $f(x)=x^{3}-102$ $f(x)=x^{2}-14 x-26$

Step 1 ：We are given the following functions: $f(x)=x^{7}-x^{5}-x^{3}-9$, $f(x)=1-x^{2}$, $f(x)=1-x^{2}+x^{3}$, $f(x)=x^{3}-102$, and $f(x)=x^{2}-14 x-26$. We need to find the function whose output decreases without bound as $x$ increases without bound.

Step 2 ：To solve this problem, we need to understand the behavior of functions as $x$ approaches infinity. The function whose output decreases without bound as $x$ increases without bound will have a negative leading coefficient. The leading coefficient is the coefficient of the term with the highest degree.

Step 3 ：Looking at the options, we can see that the function $f(x)=1-x^{2}$ has a leading coefficient of -1, which is negative. Therefore, as $x$ increases without bound, the output of this function will decrease without bound.

Step 4 ：The limit of the function $f(x)=1-x^{2}$ as $x$ approaches positive infinity and negative infinity is negative infinity. This means that the output of the function decreases without bound as $x$ increases without bound.

Step 5 ：\(\boxed{f(x)=1-x^{2}}\) is the function whose output decreases without bound as $x$ increases without bound.