Math Problem Statement

simplify (R(v)*a)^T (R(u)*b) + (R(v)*c)^T (R(u)*d + (R(u)*e x p)))

Solution

To simplify the expression (R(v)a)T(R(u)b)+(R(v)c)T(R(u)d+(R(u)e)×p)(R(v) \cdot a)^T (R(u) \cdot b) + (R(v) \cdot c)^T (R(u) \cdot d + (R(u) \cdot e) \times p), we use the properties of rotation matrices and the transposition operation. Here's a step-by-step simplification process:

Given:

  • R(v)R(v) and R(u)R(u) are rotation matrices.
  • Rotation matrices are orthogonal, i.e., R(v)T=R(v)R(v)^T = R(-v) and R(u)T=R(u)R(u)^T = R(-u).

Simplify the first term: (R(v)a)T(R(u)b)(R(v) \cdot a)^T (R(u) \cdot b)

  1. Using the property of transpose: (R(v)a)T=aTR(v)T(R(v) \cdot a)^T = a^T \cdot R(v)^T: (R(v)a)T(R(u)b)=aTR(v)TR(u)b(R(v) \cdot a)^T (R(u) \cdot b) = a^T \cdot R(v)^T \cdot R(u) \cdot b
  2. Substitute R(v)T=R(v)R(v)^T = R(-v): aTR(v)R(u)ba^T \cdot R(-v) \cdot R(u) \cdot b

Simplify the second term: (R(v)c)T(R(u)d+(R(u)e)×p)(R(v) \cdot c)^T (R(u) \cdot d + (R(u) \cdot e) \times p)

  1. Distribute the transpose using (R(v)c)T=cTR(v)T(R(v) \cdot c)^T = c^T \cdot R(v)^T: (R(v)c)T(R(u)d+(R(u)e)×p)=cTR(v)T(R(u)d+(R(u)e)×p)(R(v) \cdot c)^T (R(u) \cdot d + (R(u) \cdot e) \times p) = c^T \cdot R(v)^T \cdot (R(u) \cdot d + (R(u) \cdot e) \times p)
  2. Distribute cTR(v)Tc^T \cdot R(v)^T: cTR(v)TR(u)d+cTR(v)T(R(u)e)×pc^T \cdot R(v)^T \cdot R(u) \cdot d + c^T \cdot R(v)^T \cdot (R(u) \cdot e) \times p
  3. Substitute R(v)T=R(v)R(v)^T = R(-v): cTR(v)R(u)d+cTR(v)(R(u)e)×pc^T \cdot R(-v) \cdot R(u) \cdot d + c^T \cdot R(-v) \cdot (R(u) \cdot e) \times p

Now, recognize that R(v)R(u)R(-v) R(u) is itself a rotation matrix (let's denote it by R(w)R(w) where ww represents some rotation resulting from the combination of v-v and uu):

Combining the simplified terms:

  1. For the first term: aTR(v)R(u)b=aTR(w)ba^T \cdot R(-v) \cdot R(u) \cdot b = a^T \cdot R(w) \cdot b
  2. For the second term: cTR(v)R(u)d+cTR(v)(R(u)e)×p=cTR(w)d+cTR(w)e×pc^T \cdot R(-v) \cdot R(u) \cdot d + c^T \cdot R(-v) \cdot (R(u) \cdot e) \times p = c^T \cdot R(w) \cdot d + c^T \cdot R(w) \cdot e \times p

Thus, the simplified expression is: aTR(w)b+cTR(w)d+cTR(w)e×pa^T \cdot R(w) \cdot b + c^T \cdot R(w) \cdot d + c^T \cdot R(w) \cdot e \times p

Or, combining like terms: aTR(v)R(u)b+cTR(v)R(u)d+cTR(v)R(u)e×pa^T \cdot R(-v) \cdot R(u) \cdot b + c^T \cdot R(-v) \cdot R(u) \cdot d + c^T \cdot R(-v) \cdot R(u) \cdot e \times p

Would you like further details or have any questions?

Here are some related questions to expand your understanding:

  1. What are the properties of orthogonal matrices?
  2. How does the transpose of a rotation matrix affect its application to a vector?
  3. What is the geometric significance of the dot product in vector operations?
  4. How can multiple rotations be combined into a single rotation?
  5. What rules govern the distribution of cross products over addition?
  6. How are rotation matrices used in three-dimensional transformations?
  7. What is the impact of rotation matrices on the length and direction of vectors?
  8. How can the cross product be interpreted in terms of area?

Tip: Remember, orthogonal matrices (including rotation matrices) preserve vector norms and angles, making them particularly useful for transforming coordinate systems while maintaining the geometric properties of the vectors involved.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Matrix Algebra
Rotation Matrices
Transpose Operation
Vector Multiplication

Formulas

-

Theorems

-

Suitable Grade Level

Advanced Mathematics