Linear transformation from [-1,1] to [a,b]

Subtracting one equation from the other:2 = m(b-a)So m = 2/(b-a). Then substituting that back in either of the original equations, c = -(b+a)/(b-a).
  • #1
mercuryman
6
0
Hey
This is from Numerical analysis course (Legendre polynom) - they gave us the polynomial transformation from [-1,1] to [a,b] as: x = 2/(b-a) * z - (b+a)/(b-a)
what is the proof of this tranformation? where did it come from?
thanks
 
Physics news on Phys.org
  • #2
mercuryman said:
Hey
This is from Numerical analysis course (Legendre polynom) - they gave us the polynomial transformation from [-1,1] to [a,b] as: x = 2/(b-a) * z - (b+a)/(b-a)
what is the proof of this tranformation? where did it come from?
thanks

That isn't the transformation from [-1,1] to [a,b]; it's the transformation from [a,b] to [-1,1].

As for where it comes from: set x = mz + c, and impose the conditions that x = -1 when z = a and x = 1 when z = b. That gives you two linear simultaneous equations for m and c:
[tex]
-1 = ma + c \\
1 = mb + c
[/tex]
 

1. What is a linear transformation?

A linear transformation is a mathematical function that maps points from one n-dimensional space to another n-dimensional space while preserving the linear structure of the original space. In simpler terms, it is a transformation that preserves the straightness and direction of lines.

2. What is the domain and range of a linear transformation from [-1,1] to [a,b]?

The domain of a linear transformation from [-1,1] to [a,b] is the interval [-1,1], and the range is the interval [a,b]. This means that any input value between -1 and 1 will be transformed into an output value between a and b.

3. How is a linear transformation from [-1,1] to [a,b] represented mathematically?

A linear transformation from [-1,1] to [a,b] can be represented using a linear equation of the form y = mx + b, where m is the slope of the line and b is the y-intercept. The values of m and b will determine the specific transformation from the interval [-1,1] to [a,b].

4. What is the significance of the intervals [-1,1] and [a,b] in this linear transformation?

The interval [-1,1] represents the input values of the transformation, while [a,b] represents the corresponding output values. The interval [-1,1] is often used as the standard domain for linear transformations, and the range [a,b] can be adjusted to fit the specific needs of the transformation.

5. Can a linear transformation from [-1,1] to [a,b] have negative values in the range [a,b]?

Yes, a linear transformation from [-1,1] to [a,b] can have negative values in the range [a,b]. This will depend on the values of m and b in the linear equation y = mx + b. If the slope m is negative, the transformation will result in negative values in the range [a,b].

Similar threads

  • Linear and Abstract Algebra
Replies
8
Views
1K
Replies
27
Views
1K
  • Linear and Abstract Algebra
Replies
3
Views
1K
  • Linear and Abstract Algebra
Replies
3
Views
976
Replies
12
Views
3K
  • Linear and Abstract Algebra
Replies
3
Views
289
  • Precalculus Mathematics Homework Help
Replies
3
Views
1K
  • Linear and Abstract Algebra
Replies
2
Views
971
  • Linear and Abstract Algebra
Replies
2
Views
993
  • Linear and Abstract Algebra
Replies
1
Views
939
Back
Top