Final answer:
To guarantee that the integral is accurate, choose a sufficiently large value for n in order to get a more precise approximation using numerical methods such as Riemann sums or the trapezoidal rule.
Step-by-step explanation:
To guarantee that the integral ∫[3 to 6] (-x⁴ + 18x³ - 108x² - 4x - 5) dx is large enough, we need to determine the value of n. In this particular case, the value of n represents the number of subdivisions within the interval [3, 6] in order to approximate the integral using numerical methods such as Riemann sums or the trapezoidal rule. The larger the value of n, the more accurate the approximation will be. Therefore, to guarantee a precise result, we need to choose a sufficiently large value for n.