Please help me with this problems, it's integrals topic from Calculus textbook , thank you in advance

Question 1: [2] Explain why the Fundamental Theorem of Calculus is important. Question 2: [2] In the proof of the Fundamental Theorem of Calculus that we did (in the 'new notes'), we evaluated an integral by forming Riemann sums and taking the limit as n - co. Did we use left hand endpoints, right hand endpoints, or neither? Explain. Question 3: [1] Since we have an easier method for evaluating integrals, why do we bother with Riemann sums and taking a limit as n - co