Let's differentiate {{MATH_84}} one more time, but using chain rule and product rule. We begin by rewriting the tower function as an exponential with constant base {{MATH_85}}. {{MATH_86}} Using chain rule we find: {{ENV_87}} Rewriting {{MATH_88}} as {{MATH_89}}, we see that both methods gave the same derivative {{MATH_90}}. {{CMD_91}} {{CMD_92}}