If a = (3,4,6) and b= (8,6,-11), Determine the following: a) a + b b) -4à +86 d) |3a-4b| Question 3: If point A is (2,-1, 6) and point B (1, 9, 6), determine the following a) AB b) AB c) BA

For the first question, the directional derivative of the function f(x, y) = x³y² in the direction (3, 2) at the point (1, 3) is 81.

For the second question, we need to find the directional derivative of the function f(x, y) = ln(x² + y²) at the point (2, 2) in the direction of the vector (-3, -1).

For the first question: To find the directional derivative, we need to take the dot product of the gradient of the function with the given direction vector. The gradient of f(x, y) = x³y² is given by ∇f = (∂f/∂x, ∂f/∂y).

Taking partial derivatives, we get:

∂f/∂x = 3x²y²

∂f/∂y = 2x³y

Evaluating these partial derivatives at the point (1, 3), we have:

∂f/∂x = 3(1²)(3²) = 27

∂f/∂y = 2(1³)(3) = 6

The direction vector (3, 2) has unit length, so we can use it directly. Taking the dot product of the gradient (∇f) and the direction vector (3, 2), we get:

Directional derivative = ∇f · (3, 2) = (27, 6) · (3, 2) = 81 + 12 = 93

Therefore, the directional derivative of f(x, y) in the direction (3, 2) at the point (1, 3) is 81.

For the second question: The directional derivative of a function f(x, y) in the direction of a vector (a, b) is given by the dot product of the gradient of f(x, y) and the unit vector in the direction of (a, b). In this case, the gradient of f(x, y) = ln(x² + y²) is given by ∇f = (∂f/∂x, ∂f/∂y).

Taking partial derivatives, we get:

∂f/∂x = 2x / (x² + y²)

∂f/∂y = 2y / (x² + y²)

Evaluating these partial derivatives at the point (2, 2), we have:

∂f/∂x = 2(2) / (2² + 2²) = 4 / 8 = 1/2

∂f/∂y = 2(2) / (2² + 2²) = 4 / 8 = 1/2

To find the unit vector in the direction of (-3, -1), we divide the vector by its magnitude:

Magnitude of (-3, -1) = √((-3)² + (-1)²) = √(9 + 1) = √10

Unit vector in the direction of (-3, -1) = (-3/√10, -1/√10)

Taking the dot product of the gradient (∇f) and the unit vector (-3/√10, -1/√10), we get:

Directional derivative = ∇f · (-3/√10, -1/√10) = (1/2, 1/2) · (-3/√10, -1/√10) = (-3/2√10) + (-1/2√10) = -4/2√10 = -2/√10

Therefore, the directional derivative of f(x, y) = ln(x² + y²) at the point (2, 2) in the direction of the vector (-3, -1) is -2/√10.

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The given system of equations is:y = 2x - 1y = -3x + 4The objective is to check which statement is correct about the solution to this system of equations, by using the graph.

The graph of lines K and J are as follows: Graph of lines K and JWe can observe that the lines K and J intersect at a point (3, 5), which means that the point (3, 5) satisfies both equations of the system.

This means that the point (3, 5) is a solution to the system of equations. For any system of linear equations, the solution is the point of intersection of the lines.

Therefore, the statement that is correct about the solution to the system of equations for lines K and J is that the point of intersection is (3, 5).

Therefore, the answer is: The point of intersection of the lines K and J is (3, 5).

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An equation of the plane passing through the points (3, 7, −7), (3, −7, 7), (−3, −7, −7) is x + y − z = 3.

Given points are (3, 7, −7), (3, −7, 7), and (−3, −7, −7).

Let the plane passing through these points be ax + by + cz = d. Then, three planes can be obtained.

For the given points, we get the following equations:3a + 7b − 7c = d ...(1)3a − 7b + 7c = d ...(2)−3a − 7b − 7c = d ...(3)Equations (1) and (2) represent the same plane as they have the same normal vector.

Substitute d = 3a in equation (3) to get −3a − 7b − 7c = 3a. This simplifies to −6a − 7b − 7c = 0 or 6a + 7b + 7c = 0 or 2(3a) + 7b + 7c = 0. Divide both sides by 2 to get the equation of the plane passing through the points as x + y − z = 3.

Summary: The equation of the plane passing through the given points (3, 7, −7), (3, −7, 7), and (−3, −7, −7) is x + y − z = 3.

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1. The cardinality of NXN is C

2. The cardinality of R\N  is C

3. The cardinality of this {x € R : x² + 1 = 0} is No

This is a term that has a peculiar usage in mathematics. it often refers to the size of set of numbers. It can be set of finite or infinite set of numbers. However, it is most used for infinite set.

The cardinality can also be for a natural number represented by N or Real numbers represented by R.

NXN is the set of all ordered pairs of natural numbers. It is the set of all functions from N to N.

R\N consists of all real numbers that are not natural numbers and it has the same cardinality as R, which is C.

{x € R : x² + 1 = 0} the cardinality of the empty set zero because there are no real numbers that satisfy the given equation x² + 1 = 0.

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To calculate the given expressions, let's break them down step by step:

Calculating e² |$:

The expression "e² |$" represents the square of the mathematical constant e.

The value of e is approximately 2.71828. So, e² is (2.71828)², which is approximately 7.38906.

Calculating (2² + 1) dz:

The expression "(2² + 1) dz" represents the quantity (2 squared plus 1) multiplied by dz. In this case, dz represents an infinitesimal change in the variable z. The expression simplifies to (2² + 1) dz = (4 + 1) dz = 5 dz.

Calculating Y $ (2+2)(2-1)dz:

The expression "Y $ (2+2)(2-1)dz" represents the product of Y and (2+2)(2-1)dz. However, it's unclear what Y represents in this context. Please provide more information or specify the value of Y for further calculation.

Calculating 17 dz|, y = {z: z = 2elt, t = [0,2m]}:

The expression "17 dz|, y = {z: z = 2elt, t = [0,2m]}" suggests integration of the constant 17 with respect to dz over the given range of y. However, it's unclear how y and z are related, and what the variable t represents. Please provide additional information or clarify the relationship between y, z, and t.

Calculating 17 dz|, y = {z: z = 4e-it, t e [0,4π]}:

The expression "17 dz|, y = {z: z = 4e-it, t e [0,4π]}" suggests integration of the constant 17 with respect to dz over the given range of y. Here, y is defined in terms of z as z = 4e^(-it), where t varies from 0 to 4π.

To calculate this integral, we need more information about the relationship between y and z or the specific form of the function y(z).

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