Solving Linear Transformations in R2: Step by Step Guide

In summary, the conversation is about finding the matrix representation of a linear transformation given specific vectors and an ordered basis. The response walks through the steps of finding the image of a vector and using it to determine the matrix representation with respect to the given basis. A link to the topic is also provided for further reference.
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Fernando Revilla
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Could anyone give me a step by step method on how to solve these type of questions please? Very confused and need to know for my exams.

Let V denote the real vector space R2 and phi: V -> V be a real linear transformation such that phi((1,0)) = (4,5) and phi((0,1)) = (9,11). Express the imagine phi((x,y)) of (x,y) in terms of x and y.

Assume that w1 = (3,5) and w2 = (10,17) form an ordered basis B for V. Working from the definition determine the matrix M(subscript and superscript B) (phi) of phi with respect to the basis B.

I have given a link to the topic there so the OP can see my response.
 
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Using that $\phi$ is a linear map:
$$\phi(x,y)=\phi[x(1,0)+y(0,1)]=x\phi (1,0)+y\phi(0,1)\\=x(4,5)+y(9,11)=(4x+9y,5x+11y)$$
On the other hand:
$$\phi(w_1)=\phi (3,5)=(4\cdot 3+9\cdot 5,\;5\cdot 3+11\cdot 5)=(57,70)$$
Now, write $\phi(w_1)=(57,70)=\alpha_1w_1+\alpha_2 w_2$ and you'll easily find $\alpha_1$ and $\alpha_2$ by means of a simple system. In a similar way, you'll get $\phi(w_2)=\beta_1w_1+\beta_2 w_2$. Then,
$$M_B^B= \begin{bmatrix}{\alpha_1}&{\beta_1}\\{\alpha_2}&{ \beta_2}\end{bmatrix}=\ldots$$
 
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Related to Solving Linear Transformations in R2: Step by Step Guide

1. What are linear transformations in R2?

Linear transformations in R2 refer to mathematical operations that map points in a two-dimensional space to new points. They can be represented as matrices and can be used to translate, rotate, scale, or reflect objects in a 2D coordinate system.

2. How do I solve a linear transformation in R2?

To solve a linear transformation in R2, you will need to follow a few steps. First, identify the transformation matrix, which represents the operation being performed. Then, apply the matrix to each point in the original shape to obtain the new coordinates. Finally, plot the transformed points to see the new shape.

3. What is the purpose of solving linear transformations in R2?

The purpose of solving linear transformations in R2 is to manipulate and visualize geometric objects in a 2D space. This can be useful in various fields such as computer graphics, physics, and engineering, where understanding and manipulating shapes and objects in a 2D space is important.

4. What are some common examples of linear transformations in R2?

Some common examples of linear transformations in R2 include translation, rotation, scaling, and reflection. Translation shifts an object in a certain direction, rotation rotates an object around a fixed point, scaling changes the size of an object, and reflection creates a mirror image of an object.

5. Are there any shortcuts or techniques to make solving linear transformations in R2 easier?

Yes, there are some techniques that can make solving linear transformations in R2 easier. One technique is to break down the transformation into smaller steps and apply them one at a time. Another technique is to visualize the transformation and its effects on the shape before actually calculating the new coordinates. Additionally, using a calculator or computer software can also make the process faster and more accurate.

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