7. Which of the following equation is correct for the new Y co-ordinate if an object undergoes 3D rotation around x axis? A. Ynew = Yold x cosθ – Zold x sinθ B. Ynew = Yold x sinθ – Zold x cosθ C. Ynew = Yold x cosθ + Zold x sinθ D. Ynew = Yold x sinθ + Zold x cosθ
Ans : A Explanation: The correct equation for the new Y co-ordinate if an object undergoes 3D rotation around x axis is – Ynew = Yold x cosθ – Zold x sinθ. When the matrix form for 3D rotation around x axis is expanded then we get the following equations – Xnew = Xold; Ynew = Yold x cosθ – Zold x sinθ; Znew = Yold x sinθ + Zold x cosθ.
