Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

We are suppose to compute the quaternion which performs 1/5 of the rotation of this quaternion:

[ 0.965  (0.149  -0.149   0.149)]

The answer provided is shown as below:

Picture of the answer

I'm stuck at the second last row of the ans. How do you change from the '0.998 q0 + 0.202 q' to [0.998 0.03 -0.03 0.03]

share|cite|improve this question

Your answer omits what $q$ and $q_0$ are. I presume this is just a real linear combination of quaternions; in your peculiar notation: $$t[a\ \ (b\ \ c\ \ d)]+t'[a'\ \ (b'\ \ c'\ \ d')] =[ta+t'a'\ \ (tb+t'b'\ \ tc+t'c'\ \ td+t'd')].$$

share|cite|improve this answer
I got it. qo refers to [1 0 0 0] and q refers to the original quaternion – p0larBoy Nov 18 '10 at 8:07

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.