Applying Properties of Definite Integrals

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AP Calculus AB › Applying Properties of Definite Integrals

Questions 1 - 10
1

Given $\int_{-3}^{2} r(x),dx=-6$, what is $\int_{-3}^{2} -r(x),dx$?

$-12$

$0$

$12$

$-6$

$6$

Explanation

This problem requires applying properties of definite integrals to find the value without direct evaluation. We need to find $\int_{-3}^{2} [-r(x)],dx$ given that $\int_{-3}^{2} r(x),dx = -6$. Using the constant multiple property with $c = -1$: $\int_{-3}^{2} [-r(x)],dx = -\int_{-3}^{2} r(x),dx$. Since $\int_{-3}^{2} r(x),dx = -6$, we have $\int_{-3}^{2} [-r(x)],dx = -(-6) = 6$. A common mistake is thinking that negating the function doesn't change the integral value, leading to -6 (choice A). Remember the properties checklist: reversal changes sign, splitting uses addition, and constants factor out.

2

If $\int_{0}^{5} p(x),dx=-7$, what is $\int_{0}^{5} p(x)+2 ,dx$?

$-9$

$-5$

$7$

$3$

$-17$

Explanation

This problem requires applying properties of definite integrals to find the value without direct evaluation. We need to find $\int_{0}^{5} [p(x)+2],dx$ given that $\int_{0}^{5} p(x),dx = -7$. Using the linearity property, we can split the integral: $\int_{0}^{5} [p(x)+2],dx = \int_{0}^{5} p(x),dx + \int_{0}^{5} 2,dx$. The first integral equals -7, and the second integral equals $2(5-0) = 10$. Therefore, $\int_{0}^{5} [p(x)+2],dx = -7 + 10 = 3$. A common error is to add 2 to the integral value instead of integrating the constant 2 over the interval, which would give -5 (choice C). Remember the properties checklist: reversal changes sign, splitting uses addition, and constants factor out.

3

Given $\int_{1}^{6} h(x),dx=4$ and $\int_{1}^{3} h(x),dx=-2$, find $\int_{3}^{6} h(x),dx$.

$-6$

$-2$

$6$

$2$

$0$

Explanation

This problem requires applying properties of definite integrals to find the value without direct evaluation. We need to find $\int_{3}^{6} h(x),dx$ given $\int_{1}^{6} h(x),dx = 4$ and $\int_{1}^{3} h(x),dx = -2$. Using the additive property of integrals over adjacent intervals: $\int_{1}^{6} h(x),dx = \int_{1}^{3} h(x),dx + \int_{3}^{6} h(x),dx$. Substituting the known values: $4 = -2 + \int_{3}^{6} h(x),dx$, which gives us $\int_{3}^{6} h(x),dx = 6$. A common mistake is subtracting the integrals instead of using the additive property correctly, which might lead to -6 (choice A). Remember the properties checklist: reversal changes sign, splitting uses addition, and constants factor out.

4

If $\int_{1}^{9} s(x),dx=-10$, what is $\int_{1}^{9} \left(s(x)+5\right),dx$?

$-50$

$-55$

$30$

$50$

$-30$

Explanation

This question assesses the skill of applying properties of definite integrals. Linearity splits into the integral of s plus 5 times the integral of 1. That's -10 + 5*8 = -10 + 40 = 30. The constant uses the interval length of 8. A tempting distractor is -50, which subtracts instead of adding. When working with definite integrals, remember this checklist: additivity over adjacent intervals, scalar multiples factor out, reversing limits adds a negative sign, and constants integrate to the constant times the interval length.

5

Given $\int_{-5}^{0} r(x),dx=6$ and $\int_{0}^{4} r(x),dx=-1$, what is $\int_{-5}^{4} r(x),dx$?

$5$

$-5$

$7$

$-7$

$1$

Explanation

This question assesses the skill of applying properties of definite integrals. Additivity combines from $-5$ to $0$ and $0$ to $4$ into $-5$ to $4$. Summing $6$ and $-1$ gives $5$. This property handles the split intervals. A tempting distractor is $7$, which ignores the negative sign. When working with definite integrals, remember this checklist: additivity over adjacent intervals, scalar multiples factor out, reversing limits adds a negative sign, and constants integrate to the constant times the interval length.

6

If $\int_{5}^{9} t(x),dx=0$, what is $\int_{5}^{9} \left(7t(x)\right),dx$?

$9$

$7$

$-7$

$0$

$-9$

Explanation

This question assesses the skill of applying properties of definite integrals. The scalar multiple property factors out the 7, giving 7 times the integral of t(x), which is 7 * 0 = 0. This holds regardless of the function since the base integral is zero. No additional computation is required. A tempting distractor is 7, which ignores that the integral is zero. When working with definite integrals, remember this checklist: additivity over adjacent intervals, scalar multiples factor out, reversing limits adds a negative sign, and constants integrate to the constant times the interval length.

7

Given $\int_{-1}^{4} q(x),dx=-2$, find $\int_{-1}^{4} \left(-2q(x)\right),dx$.

$4$

$0$

$-1$

$1$

$-4$

Explanation

This question assesses the skill of applying properties of definite integrals. The scalar multiple property allows us to factor out -2 from the integral, giving -2 times the given integral of -2. This results in -2 * -2 = 4. No further evaluation is needed due to this property. A tempting distractor is -4, which might occur by forgetting to apply the scalar to the given value correctly. When working with definite integrals, remember this checklist: additivity over adjacent intervals, scalar multiples factor out, reversing limits adds a negative sign, and constants integrate to the constant times the interval length.

8

If $\int_{0}^{10} p(x),dx=13$, what is $\int_{0}^{10} \left(p(x)-1\right),dx$?

$-3$

$-12$

$3$

$12$

$23$

Explanation

This question assesses the skill of applying properties of definite integrals. The linearity property lets us split the integral of p(x) - 1 into the integral of p(x) minus the integral of 1. The integral of 1 from 0 to 10 is 10, so 13 - 10 equals 3. This uses the constant integral rule alongside linearity. A tempting distractor is 23, which adds 10 instead of subtracting. When working with definite integrals, remember this checklist: additivity over adjacent intervals, scalar multiples factor out, reversing limits adds a negative sign, and constants integrate to the constant times the interval length.

9

Given $\int_{-2}^{3} g(x),dx=9$, what is $\int_{-2}^{3} \left(g(x)-g(x)\right),dx$?

$-18$

$18$

$9$

$-9$

$0$

Explanation

This question assesses the skill of applying properties of definite integrals. The expression g(x) - g(x) simplifies to 0, and the integral of 0 is 0. Linearity confirms this result regardless of the given value. No computation of the original integral is needed. A tempting distractor is 9, which uses the given value without simplifying the integrand. When working with definite integrals, remember this checklist: additivity over adjacent intervals, scalar multiples factor out, reversing limits adds a negative sign, and constants integrate to the constant times the interval length.

10

Given $\int_{0}^{2} p(x),dx=-4$ and $\int_{2}^{4} p(x),dx=9$, find $\int_{0}^{4} p(x),dx$.

$5$

$13$

$-5$

$9$

$-13$

Explanation

This question assesses the skill of applying properties of definite integrals. Additivity sums the integrals from 0 to 2 and 2 to 4 into 0 to 4. That's -4 + 9 = 5. This merges the given values directly. A tempting distractor is -13, which subtracts instead of adding. When working with definite integrals, remember this checklist: additivity over adjacent intervals, scalar multiples factor out, reversing limits adds a negative sign, and constants integrate to the constant times the interval length.

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