⚠ f(x)=(1-e^{x^2})/(1-e^{1-x^2)} is read as f(x)=(1-e^(x^2))/(1-e^(1-x^2)) We save the definition: f(x) = 1 -ex21 -e(1 -x2) Let's find the domain of 1 -ex21 -e(1 -x2) For the expression 1 -ex21 -e(1 -x2) to be defined, we must have: 1 -e(1 -x2) ≠ 0 You can apply the ln function on both sides: ln(e(1 -x2)) ≠ ln(1) ℹln(e(1 -x2)) = 1 -x2‖ln(1) = 0 1 -x2 ≠ 0 ▶Domain of definition: x ∈ ℝ \ { -1, 1 }