answersLogoWhite

0

It comes from the Law of Cosines.

* * * * *

For any two vectors A and B, the projection of A onto B, that is, the component of A along B, is ab.cos(x) where x is the angle between the two vectors. By symmetry, this is also the projectoin of B onto A.

User Avatar

Wiki User

14y ago

What else can I help you with?

Continue Learning about Math & Arithmetic

Why you use cos in scalar product?

The cosine function is used in the scalar product (or dot product) because it quantifies the angle between two vectors. The scalar product is defined as the product of the magnitudes of the two vectors multiplied by the cosine of the angle between them. This relationship captures how aligned the vectors are: when they point in the same direction, the cosine is 1, and when they are perpendicular, the cosine is 0. Thus, using cosine allows us to measure both the magnitude and directional alignment of the vectors in the product.


How angle between two vectors is found using cross product?

A x B = |A| |B| sin[theta]


How you find cos data?

To find cosine data, you can use a scientific calculator or a trigonometric table that provides cosine values for specific angles. Additionally, programming languages like Python or software tools like Excel can compute cosine values using built-in functions. For angles measured in radians, you can also apply the cosine function directly using the formula cos(θ), where θ is the angle in radians. Online resources and mathematical software can also provide cosine values for various angles quickly.


How does the angle vectors affect the resultant vector?

The angle between two vectors significantly influences the magnitude and direction of the resultant vector. When two vectors are aligned in the same direction, their magnitudes simply add up, resulting in a larger resultant vector. Conversely, if they are at an angle to each other, the resultant vector's magnitude can be calculated using the cosine rule, and its direction is determined by the vector addition process. The greater the angle between the vectors, the more the resultant vector's magnitude can be diminished.


What is defined as force times distance?

Work is defined as the dot product of force times distance, or W = F * d = Fd cos (theta) where theta is the angle in between the force and distance vectors (if you are doing two dimensions). In three dimensions, use the standard definition for the dot product (using the component form of the vectors).

Related Questions

How do you do rotation in math?

A vector rotation in math is done on a coordinate plane.2D vectors can be rotated using the cross and dot product.3D vectors are rotated using matrix based quaternion math.


How angle between two vectors is found using cross product?

A x B = |A| |B| sin[theta]


What are sine and cosine functions?

Sine allows us to find out what a third side or an angle is using the equation sin(x) = opposite over hypotenuse (x being the angle). Cosine has the same function but instead uses the equation cosine(x)= opposite over adjacent


What is the cross product of two perpendicular vectors and how is it calculated?

The cross product of two perpendicular vectors is a vector that is perpendicular to both of the original vectors. It is calculated using the formula: mathbfa times mathbfb beginpmatrix a2b3 - a3b2 a3b1 - a1b3 a1b2 - a2b1 endpmatrix Where (mathbfa beginpmatrix a1 a2 a3 endpmatrix) and (mathbfb beginpmatrix b1 b2 b3 endpmatrix) are the two perpendicular vectors.


How you find cos data?

To find cosine data, you can use a scientific calculator or a trigonometric table that provides cosine values for specific angles. Additionally, programming languages like Python or software tools like Excel can compute cosine values using built-in functions. For angles measured in radians, you can also apply the cosine function directly using the formula cos(θ), where θ is the angle in radians. Online resources and mathematical software can also provide cosine values for various angles quickly.


How does the angle vectors affect the resultant vector?

The angle between two vectors significantly influences the magnitude and direction of the resultant vector. When two vectors are aligned in the same direction, their magnitudes simply add up, resulting in a larger resultant vector. Conversely, if they are at an angle to each other, the resultant vector's magnitude can be calculated using the cosine rule, and its direction is determined by the vector addition process. The greater the angle between the vectors, the more the resultant vector's magnitude can be diminished.


How do you solve COS?

To solve for the cosine (COS) of an angle, you can use the unit circle, where the cosine of an angle corresponds to the x-coordinate of the point on the circle at that angle. Alternatively, you can use trigonometric identities or the cosine function on a scientific calculator by inputting the angle in degrees or radians. For specific problem solving, using the cosine rule in triangles may also be applicable to find unknown sides or angles.


What should be the angle between 2 vectors a?

The angle between two vectors a and b can be found using the dot product formula: a · b = |a| |b| cos(theta), where theta is the angle between the two vectors. Rearranging the formula, we can solve for theta: theta = arccos((a · b) / (|a| |b|)).


What are the different methods in adding vectors?

Vectors can be added using the component method, where you add the corresponding components of the vectors to get the resultant vector. You can also add vectors using the graphical method, where you draw the vectors as arrows and then add them tip-to-tail to find the resultant vector. Additionally, vectors can be added using the trigonometric method, where you use trigonometry to find the magnitude and direction of the resultant vector.


What is defined as force times distance?

Work is defined as the dot product of force times distance, or W = F * d = Fd cos (theta) where theta is the angle in between the force and distance vectors (if you are doing two dimensions). In three dimensions, use the standard definition for the dot product (using the component form of the vectors).


What is the angle between unit vectors i plus j and j plus k?

The angle between two vectors can be found using the dot product formula: A · B = |A| |B| cos(theta). In this case, the dot product of the two given unit vectors is (1)(0) + (1)(1) + (0)(1) = 1. The magnitudes of the vectors are √2 and √2, therefore cos(theta) = 1 / (2)(2) = 1/4, giving theta = arccos(1/4) ≈ 75.5 degrees.


How do you work out an angle using trigonometry?

Using the Sine function Sin(x) = 0.5 Then x = Sin^(-1)0.5 x = 30 degrees. Sin^(-1) in the inverse function on you calculator. . It works for Sin , Cosine and Tangent of any angle.