Binayak Bhaiya

Chapter 14 – Mathematical Reasoning (Ex – 14.5)

Mathematical Reasoning (Ex – 14.5) Question 1.Show that the statementp: “If x is a real number such that x3 + 4x = 0, then x is 0″ is true by(i) direct method,(ii) method of contradiction,(iii) method of contrapositive. Solution:The given compound statement is of the form “if p then q”p: x ϵ R such that x3 + 4x = 0q:

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Chapter 14 – Mathematical Reasoning (Ex – 14.4)

Mathematical Reasoning (Ex – 14.4) Question 1.Rewrite the following statement with “if-then” in five different ways conveying the same meaning. If a natural number is odd, then its square is also odd. Solution:(i) A natural number is odd implies that its square is odd.(ii) A natural number is odd only if its square is odd.(iii) For a natural

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Chapter 14 – Mathematical Reasoning (Ex – 14.3)

Mathematical Reasoning (Ex – 14.3) Question 1.For each of the following compound statements first, identify the connecting words and then break it into component statements.(i) All rational numbers are real and all real numbers are not complex.(ii) Square of an integer is positive or negative.(iii) The sand heats up quickly in the Sun and does not cool down

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Chapter 14 – Mathematical Reasoning (Ex – 14.2)

Mathematical Reasoning (Ex – 14.2) Question 1.Write the negation of the following statements:(i) Chennai is the capital of Tamil Nadu.(ii) √2 is not a complex number.(iii) All triangles are not equilateral triangle.(iv) The number 2 is greater than 7.(v) Every natural number is an integer. Solution:(i) Negation of statement is: Chennai is not the capital of Tamil Nadu.(ii) Negation of statement is: √2 is a

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Chapter 14 – Mathematical Reasoning (Ex – 14.1)

Mathematical Reasoning (Ex – 14.1) Question 1.Which of the following sentences are statements? Give reasons for your answer.(i) There are 35 days in a month.(ii) Mathematics is difficult.(iii) The sum of 5 and 7 is greater than 10.(iv) The square of a number is an even number.(v) The sides of a quadrilateral have equal length.(vi) Answer this question.(vii) The product of (-1)

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Chapter 13 – Limits and Derivatives (Ex – 13.2)

Limits and Derivatives (Ex – 13.2) Question 1.Find the derivative of x2 – 2 at x = 10. Solution:let f(x) = x2 – 2Differentiating (i) with respect to x, we getf'(x) = 2xAt x = 10, f'(10) = 2(10) = 20. Question 2.Find the derivative of 99x at x = 10. Solution:let f(x) = 99xDifferentiating (i) with respect to

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Chapter 13 – Limits and Derivatives (Ex – 13.1)

Limits and Derivatives (Ex – 13.1) Evaluate the following limits in Exercises 1 to 22. Question 1. Solution: Question 2. Solution: Question 3. Solution: Question 4. Solution: Question 5. Solution: Question 6. Solution: Question 7. Solution: Question 8. Solution: Question 9. Solution: Question 10. Solution: Question 11. Solution: Question 12. Solution: Question 13. Solution: Question

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Chapter 12 – Introduction to Three Dimensional Geometry (Ex – 12.3)

Introduction to Three Dimensional Geometry (Ex – 12.3) Question 1.Find the coordinates of the point which divides the line segment joining the points (-2, 3, 5) and (1, -4, 6) in the ratio(i) 2 : 3 internally,(ii) 2 : 3 externally Solution:(i) Let P(x, y, z) be any point which divides the line segment joining the points A(-2,

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Chapter 12 – Introduction to Three Dimensional Geometry (Ex – 12.2)

Introduction to Three Dimensional Geometry (Ex – 12.2) Question 1.Find the distance between the following pairs of points:(i) (2, 3, 5) and (4, 3, 1)(ii) (-3, 7, 2) and (2, 4, -1)(iii) (-1, 3, -4) and (1, -3, 4)(iv) (2, -1, 3) and (-2, 1, 3) Solution: Question 2.Show that the points (-2, 3, 5), (1, 2, 3) and

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