# 22 Lecture

## MTH101

### Midterm & Final Term Short Notes

## Relative Extrema

Relative extrema are the local maximum or minimum values of a function in a given interval. In other words, they are the highest or lowest points within a particular range of the function.

**Important Mcq's**

Midterm & Finalterm Prepration

Past papers included

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**What is a relative extremum?**

A. A point where the function is undefined.

B. A point where the function has a vertical tangent.

C. A local maximum or minimum value of a function within a given interval.

D. A point where the function has a horizontal tangent.

Answer: C. A local maximum or minimum value of a function within a given interval.

**How do you find relative extrema?**

A. Take the limit of the function as x approaches infinity.

B. Take the limit of the function as x approaches negative infinity.

C. Take the derivative of the function and find the critical points.

D. Take the integral of the function.

Answer: C. Take the derivative of the function and find the critical points.

**What is a critical point in calculus?**

A. A point where the function is undefined.

B. A point where the function has a vertical tangent.

C. A point where the derivative of the function is zero or undefined.

D. A point where the function has a horizontal tangent.

Answer: C. A point where the derivative of the function is zero or undefined.

**What is the second derivative test?**

A. A method used to determine whether a critical point corresponds to a relative maximum, relative minimum, or neither.

B. A method used to find the derivative of the function.

C. A method used to find the antiderivative of the function.

D. A method used to find the limit of the function as x approaches infinity.

Answer: A. A method used to determine whether a critical point corresponds to a relative maximum, relative minimum, or neither.

**What is a relative maximum?**

A. The highest point of a function within a given interval.

B. The lowest point of a function within a given interval.

C. A point where the function is undefined.

D. A point where the function has a vertical tangent.

Answer: A. The highest point of a function within a given interval.

**What is a relative minimum?**

A. The highest point of a function within a given interval.

B. The lowest point of a function within a given interval.

C. A point where the function is undefined.

D. A point where the function has a vertical tangent.

Answer: B. The lowest point of a function within a given interval.

**Can a function have multiple relative extrema?**

A. Yes, a function can have multiple relative extrema.

B. No, a function can only have one relative extremum.

C. It depends on the type of function.

D. It depends on the interval.

Answer: A. Yes, a function can have multiple relative extrema.

**What is the second derivative of a function?**

A. The derivative of its antiderivative.

B. The integral of its derivative.

C. The derivative of its first derivative.

D. The integral of its second derivative.

Answer: C. The derivative of its first derivative.

**What is a point of inflection?**

A. A point where the function is undefined.

B. A point where the function has a vertical tangent.

C. A point where the function changes concavity.

D. A point where the function has a horizontal tangent.

Answer: C. A point where the function changes concavity.

**What is the critical number of a function?**

A. The highest point of the function.

B. The lowest point of the function.

C. The point where the function is undefined.

D. The value of x that makes the derivative zero or undefined.

Answer: D. The value of x that makes the derivative zero or undefined.

**Subjective Short Notes**

Midterm & Finalterm Prepration

Past papers included

Download PDF
**What are relative extrema?**

**Answer:** Relative extrema are the local maximum or minimum values of a function within a given interval.

**How do you find relative extrema?**

**Answer:** To find relative extrema, we take the first derivative of the function, set it equal to zero, and solve for x. We then use the second derivative test to determine the nature of each critical point.

**What is a critical point in calculus?**

**Answer:** A critical point in calculus is a point on the function where the derivative is zero or undefined.

**What is the second derivative test?**

**Answer:** The second derivative test is a method used to determine whether a critical point corresponds to a relative maximum, relative minimum, or neither.

**What is the second derivative of a function?**

**Answer:** The second derivative of a function is the derivative of its first derivative.

**What is a relative maximum?**

**Answer:** A relative maximum is the highest point of a function within a given interval.

**What is a relative minimum?**

**Answer:** A relative minimum is the lowest point of a function within a given interval.

**Can a function have more than one relative maximum or minimum?**

**Answer: **Yes, a function can have multiple relative extrema.

**What are some applications of relative extrema in economics?**

**Answer:** Relative extrema can represent the maximum or minimum values of a cost function, profit function, or utility function in economics.

**What are some applications of relative extrema in physics?**

**Answer:** Relative extrema can represent the maximum or minimum values of a velocity or acceleration function in physics.

### Relative Extrema

In calculus, extrema refer to the maximum and minimum values of a function. These can occur at specific points on the function, called extrema points or critical points. Relative extrema are the local maximum or minimum values of a function in a given interval. In other words, they are the highest or lowest points within a particular range of the function. To find relative extrema, we need to take the first derivative of the function, set it equal to zero, and solve for x. The resulting values are the critical points of the function. We then use the second derivative test to determine whether each critical point corresponds to a relative maximum, relative minimum, or neither. The second derivative test involves evaluating the second derivative of the function at each critical point. If the second derivative is positive, the critical point corresponds to a relative minimum. If the second derivative is negative, the critical point corresponds to a relative maximum. If the second derivative is zero, the test is inconclusive and we need to use additional methods to determine the nature of the critical point.**Let's take a closer look at the process of finding relative extrema with an example. Consider the function f(x) = x^3 - 3x^2 + 2x + 1. We first take the derivative of the function:**f'(x) = 3x^2 - 6x + 2 We then set this equal to zero and solve for x: 3x^2 - 6x + 2 = 0 x = (-b ± sqrt(b^2 - 4ac))/(2a) x = (-(-6) ± sqrt((-6)^2 - 4(3)(2)))/(2(3)) x = (6 ± sqrt(12))/6 x = 1 ± sqrt(3)/3 We now have two critical points: x = 1 + sqrt(3)/3 and x = 1 - sqrt(3)/3. To determine whether these correspond to relative maxima or minima, we need to evaluate the second derivative of the function: f''(x) = 6x - 6 At x = 1 + sqrt(3)/3, f''(x) = 6(1 + sqrt(3)/3) - 6 = 2sqrt(3) > 0, so this critical point corresponds to a relative minimum. At x = 1 - sqrt(3)/3, f''(x) = 6(1 - sqrt(3)/3) - 6 = -2sqrt(3) < 0, so this critical point corresponds to a relative maximum. Therefore, the function has a relative minimum at x = 1 + sqrt(3)/3 and a relative maximum at x = 1 - sqrt(3)/3. Relative extrema are important in many applications of calculus. For example, in economics, relative extrema can represent the maximum or minimum values of a cost function, profit function, or utility function. In physics, relative extrema can represent the maximum or minimum values of a velocity or acceleration function.

**In conclusion,**relative extrema are the local maximum or minimum values of a function within a given interval. To find them, we take the first derivative of the function, set it equal to zero, and solve for x. We then use the second derivative test to determine the nature of each critical point. Relative extrema are essential in many applications of calculus, and understanding how to find them is an important skill for any student of calculus and analytical geometry.