Q. Find the value of x for which the function f(x) = x^3 - 6x^2 + 9x has an inflection point.
Solution
To find inflection points, set f''(x) = 0. f''(x) = 6x - 12. Setting 6x - 12 = 0 gives x = 2.
Correct Answer:
B
— 2
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Q. Find the value of x where the function f(x) = x^3 - 6x^2 + 9x has a local minimum. (2020)
Solution
Setting f'(x) = 3x^2 - 12x + 9 = 0 gives x = 1, 3. Testing shows x = 2 is a local minimum.
Correct Answer:
B
— 2
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Q. Find the value of x where the function f(x) = x^3 - 6x^2 + 9x has an inflection point.
-
A.
x = 1
-
B.
x = 2
-
C.
x = 3
-
D.
x = 0
Solution
To find inflection points, set f''(x) = 0. f''(x) = 6x - 12. Setting it to zero gives x = 2.
Correct Answer:
B
— x = 2
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Q. For the cubic equation x^3 - 3x^2 + 3x - 1 = 0, which of the following is a root?
Solution
By substituting x = 1 into the equation, we find that it satisfies the equation, hence 1 is a root.
Correct Answer:
C
— 1
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Q. For the cubic equation x^3 - 3x^2 + 3x - 1 = 0, which of the following is true about its roots?
-
A.
All roots are real
-
B.
All roots are complex
-
C.
One root is real and two are complex
-
D.
Two roots are real and one is complex
Solution
The roots can be found using the Rational Root Theorem and synthetic division, confirming that all roots are real.
Correct Answer:
A
— All roots are real
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Q. For the data set 2, 3, 3, 4, 4, 4, 5, 5, what is the mode?
Solution
The mode is 4, as it appears 3 times, more than any other number.
Correct Answer:
C
— 4
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Q. For the data set: 1, 2, 3, 4, 5, what is the variance? (2022)
Solution
Mean = (1 + 2 + 3 + 4 + 5) / 5 = 3. Variance = [(1-3)² + (2-3)² + (3-3)² + (4-3)² + (5-3)²] / 5 = 2.
Correct Answer:
B
— 1.5
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Q. For the data set: 10, 12, 14, 16, 18, calculate the variance. (2020)
Solution
Mean = (10 + 12 + 14 + 16 + 18) / 5 = 14. Variance = [(10-14)² + (12-14)² + (14-14)² + (16-14)² + (18-14)²] / 5 = 8.
Correct Answer:
A
— 8
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Q. For the data set: 10, 12, 14, 16, what is the variance? (2019)
Solution
Mean = (10 + 12 + 14 + 16) / 4 = 13. Variance = [(10-13)² + (12-13)² + (14-13)² + (16-13)²] / 4 = 2.
Correct Answer:
B
— 4
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Q. For the data set: 2, 4, 6, 8, 10, what is the variance? (2023)
Solution
Mean = (2 + 4 + 6 + 8 + 10) / 5 = 6. Variance = [(2-6)² + (4-6)² + (6-6)² + (8-6)² + (10-6)²] / 5 = 8.
Correct Answer:
A
— 6
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Q. For the data set: 3, 3, 3, 3, 3, what is the variance? (2023)
Solution
All values are the same, so variance = 0.
Correct Answer:
A
— 0
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Q. For the data set: 5, 7, 9, 11, 13, what is the variance?
Solution
Mean = 9. Variance = [(5-9)² + (7-9)² + (9-9)² + (11-9)² + (13-9)²] / 5 = 8.
Correct Answer:
A
— 4
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Q. For the data set: 5, 8, 12, 15, 20, what is the median? (2020)
Solution
Arranging the numbers: 5, 8, 12, 15, 20. The median is the middle number, which is 12.
Correct Answer:
A
— 12
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Q. For the data set: 6, 7, 8, 8, 9, 9, 9, 10, what is the mode?
Solution
The mode is 9, as it appears most frequently (three times) in the data set.
Correct Answer:
D
— 9
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Q. For the equation x^2 + 2x + 1 = 0, what is the nature of the roots?
-
A.
Real and distinct
-
B.
Real and equal
-
C.
Complex
-
D.
None of the above
Solution
The discriminant is 2^2 - 4(1)(1) = 0, indicating that the roots are real and equal.
Correct Answer:
B
— Real and equal
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Q. For the equation x^2 + 4x + k = 0 to have real roots, what must be the condition on k? (2023)
-
A.
k >= 0
-
B.
k <= 0
-
C.
k >= 16
-
D.
k <= 16
Solution
The discriminant must be non-negative: 4^2 - 4*1*k >= 0 leads to 16 - 4k >= 0, thus k <= 4.
Correct Answer:
C
— k >= 16
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Q. For the equation x^2 + 6x + k = 0 to have no real roots, what must be the condition on k?
-
A.
k < 0
-
B.
k > 0
-
C.
k = 0
-
D.
k ≤ 0
Solution
The condition for no real roots is that the discriminant must be less than zero: 6^2 - 4*1*k < 0 => 36 < 4k => k > 9.
Correct Answer:
D
— k ≤ 0
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Q. For the equation x^3 - 3x^2 + 3x - 1 = 0, how many real roots does it have?
Solution
The equation can be factored as (x-1)^3 = 0, which has one real root (x = 1) with multiplicity 3.
Correct Answer:
A
— 1
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Q. For the equation x^3 - 4x^2 + 5x - 2 = 0, which of the following is a root? (2023)
Solution
By substituting x = 2 into the equation, we find that it satisfies the equation, thus x = 2 is a root.
Correct Answer:
B
— 2
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Q. For the equation x^3 - 6x^2 + 11x - 6 = 0, what is the product of the roots? (2019)
Solution
The product of the roots of the cubic equation ax^3 + bx^2 + cx + d = 0 is given by -d/a. Here, d = -6 and a = 1, so the product is -(-6)/1 = 6.
Correct Answer:
A
— 6
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Q. For the equation x^3 - 6x^2 + 11x - 6 = 0, which of the following is a root?
Solution
By substituting x = 2 into the equation, we find that 2 is a root since 2^3 - 6(2^2) + 11(2) - 6 = 0.
Correct Answer:
B
— 2
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Q. For the function f(x) = -x^2 + 4x + 1, find the maximum value. (2023)
Solution
The maximum occurs at x = -b/(2a) = -4/(-2) = 2. f(2) = -2^2 + 4(2) + 1 = 5.
Correct Answer:
B
— 5
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Q. For the function f(x) = 3x^2 - 12x + 7, find the coordinates of the minimum point. (2019)
-
A.
(2, -5)
-
B.
(2, -1)
-
C.
(4, 1)
-
D.
(4, -5)
Solution
The vertex is at x = -(-12)/(2*3) = 2. The minimum value is f(2) = 3(2^2) - 12(2) + 7 = -5. Thus, the coordinates are (2, -5).
Correct Answer:
A
— (2, -5)
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Q. For the function f(x) = e^x, what is f''(x)? (2021)
Solution
The second derivative f''(x) = d/dx(e^x) = e^x.
Correct Answer:
A
— e^x
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Q. For the function f(x) = sin(x) + cos(x), what is f'(π/4)? (2023)
Solution
f'(x) = cos(x) - sin(x). At x = π/4, f'(π/4) = cos(π/4) - sin(π/4) = √2/2 - √2/2 = 0.
Correct Answer:
B
— √2
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Q. For the function f(x) = sin(x), what is f'(π/2)? (2021)
-
A.
0
-
B.
1
-
C.
-1
-
D.
undefined
Solution
f'(x) = cos(x); f'(π/2) = cos(π/2) = 0.
Correct Answer:
B
— 1
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Q. For the function f(x) = x^2 - 6x + 10, what is the minimum value? (2020)
Solution
The vertex is at x = 6/2 = 3. The minimum value is f(3) = 3^2 - 6*3 + 10 = 1.
Correct Answer:
B
— 3
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Q. For the function f(x) = x^3 - 3x + 2, find the points of discontinuity.
-
A.
None
-
B.
x = 1
-
C.
x = -1
-
D.
x = 2
Solution
f(x) is a polynomial function and is continuous everywhere, hence no points of discontinuity.
Correct Answer:
A
— None
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Q. For the function f(x) = { 2x + 1, x < 1; 3, x = 1; x^2, x > 1 }, is f(x) continuous at x = 1?
-
A.
Yes
-
B.
No
-
C.
Only left continuous
-
D.
Only right continuous
Solution
The left limit as x approaches 1 is 3, the right limit is 1, and f(1) = 3. Since the limits do not match, f(x) is discontinuous at x = 1.
Correct Answer:
B
— No
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Q. For the function f(x) = { x^2, x < 0; 0, x = 0; x + 1, x > 0 }, is f(x) continuous at x = 0?
-
A.
Yes
-
B.
No
-
C.
Only left continuous
-
D.
Only right continuous
Solution
The left limit as x approaches 0 is 0, the right limit is 1, and f(0) = 0. Since the limits do not match, f(x) is discontinuous at x = 0.
Correct Answer:
B
— No
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