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Solve the following.
Show that ∫₅¹ f(x) dx = -4.
Show that $\int_5^1 f(x) dx = -4$.
Answer
Answer
Official answer key$\int_1^5 3f(x)\,dx = 12$, so $\int_1^5 f(x)\,dx = 4$.
Reversing the limits changes the sign: $\int_5^1 f(x)\,dx = -\int_1^5 f(x)\,dx = -4$. Hence shown.