Update BENCHMARKS.md

Author: kmolan

BENCHMARKS.md

@@ -88,6 +88,6 @@ Integrand                              | Approximation error |           Notes
 -------------------------------------- | ------------------- | ------------------------------------------------------- |
 $$\int_{-\infty}^\infty x^2 e^{-x^2} \mathrm{d}x$$   | 1e-30              |  Trivial Integration to showcase accuracy levels    |
 $$\int_{-\infty}^\infty (4x^3 - 3x^2)e^{-x^2} \mathrm{d}x$$  | 1e-12      |   High accuracy for more complicated integrands      |
-$$\int_{0}^\infty\int_{0}^\infty\int_{0}^\infty (x^3 y + y^3 z)e^{-x^2} \mathrm{d}x\mathrm{d}x\mathrm{d}y$$ | 1e-9 | High accuracy for higher order integrals|
+$$\int_{-\infty}^\infty\int_{-\infty}^\infty\int_{-\infty}^\infty (x^3 y + y^3 z)e^{-x^2} \mathrm{d}x\mathrm{d}x\mathrm{d}y$$ | 1e-9 | High accuracy for higher order integrals|
 $$\int_{-\infty}^\infty (Sin(x) - \sqrt{x})e^{-x^2} \mathrm{d}x$$ | 1e-1 | Poor performance for non-polynomial integrands |