Review: Introductory Calculus: Integrals and Accumulation
Integration connects signed accumulation with limiting sums. Rectangle models approximate that accumulation, antiderivatives evaluate suitable definite integrals, and the Fundamental Theorem links an accumulation function’s derivative to its continuous integrand.
Bring the unit skills together
Use these 4 new cases to check your reasoning. Choices are temporary and are not saved to an account, sent to staff or recorded as school grades. Download your current review choices before leaving or reloading.
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Use the skills in a new task
Create a four-part mathematical solution sheet for these supplied cases. 1. Approximate accumulation over three equal intervals of width 9 using supplied heights 1,2,3. What is the rectangle sum? Candidate answers: (A) 108 (B) 53 (C) 54 (D) 55. 2. Evaluate the definite integral of 2x from 0 to 9. Candidate answers: (A) 162 (B) 80 (C) 81 (D) 82. 3. A supplied graph has geometric area 27 above the x-axis and 18 below, over one interval. Find its definite integral. Candidate answers: (A) 10 (B) 18 (C) 8 (D) 9. 4. Let F(x)=integral from 0 to x of (t²+1) dt. Find F′(9). Candidate answers: (A) 164 (B) 81 (C) 82 (D) 83.
Work on paper or in your own document. Explain the choices you made.
- State each requested quantity or relationship and its input restrictions.
- Show intermediate calculations or the applicable theorem with matching correspondences.
- Give all four results, including exact values or requested rounding and units.
- Check a result by substitution, reversal, dimensions, a representation or a counterexample as appropriate.
Compare with a model response
1. 54. Each rectangle contributes height×width. Sum 9×1+9×2+9×3=54. Without the actual function, these supplied heights define an approximation, not a certified error bound. 2. 81. An antiderivative of 2x is x². Evaluate at the bounds and subtract: 9²−0²=81. The additive constant cancels in a definite integral. 3. 9. The definite integral accumulates signed area: 27−18=9. The total geometric area would add them to 45, which answers a different question. 4. 82. The integrand is continuous, so the Fundamental Theorem gives F′(x)=x²+1. At 9, this equals 82. No integration constant or extra power is needed.
A different response can also meet the criteria. Compare the evidence and reasoning, rather than copying the wording.