- #1

Identify

- 12

- 0

## Homework Statement

Prove that d/dt[

**r**.(

**v**x

**a**)] =

**r**.(

**v**xd

**a**/dt)

## Homework Equations

**r**,

**v**,

**a**are position, velocity and acceleration vectors.

..

**r**.(

**v**.. is the dot product.

..

**v**x

**a**.. is the cross product

## The Attempt at a Solution

I expand the equation using the product rule for dot and cross products to get:

d

**r**/dt.(

**v**x

**a**)+

**r**.(d

**v**/dt x

**a**+

**v**x d

**a**/dt)

I've expanded this further on paper using the x,y,z components of each vector but i can't manipulate it to get the desired result? Have I missed a step or overlooked something here?