Understand Composition of Functions: Understand the composition of functions. The composition of two functions, f∘g)(n)meansthatwefirstapply$g to n, and then apply f to the result of g(n). So, f∘g)(10)meansweneedtofind$g(10) first and then apply f to that result.
Calculate g(10): Calculate g(10). We have g(n)=n2−n. So, g(10)=102−10=100−10=90.
Apply f to g(10): Apply f to the result of g(10). Now we need to apply f to 90, since we found that g(10)=90. The function f(n) is defined as f(n)=10n. So, f(90)=10×90.