Given: f(x)=x2−1f(x) = x^2 - 1f(x)=x2−1 Substitute x=−3x = -3x=−3: f(−3)=(−3)2−1=9−1=8\begin{aligned} f(-3) &= (-3)^2 - 1 \\ &= 9 - 1 \\ &= 8 \end{aligned}f(−3)=(−3)2−1=9−1=8 f(−3)=8\boxed{f(-3) = 8}f(−3)=8