Week 3 Tutorial
Remember, you must attempt the tutorial problems before the tutorial.
Question 1
Calculate the transformation matrix for rotation about (0,2) by 60°. Hint: You can do it as a product of a translation, then a rotation about the origin, and then a translation.
Question 2
Show that the order in which transformations is important by first sketching the result when triangle A(1,0), B(1,1), C(0,1) is rotating by 45° about the origin and then translated by (1,0), and then sketch the result when it is first translated and then rotated.
Question 3
A shear transformation maps the unit square A(0,0), B(1,0), C(1,1), D(0,1) to A‘(0,0), B‘(1,0), C‘(1+h,1), D‘(h,1).

Find the transformation matrix for this transformation. (Hint: Let
![T=\left[\begin{array}{ccc}a&b&c\\d&e&f\\0&0&1\end{array}\right] T=\left[\begin{array}{ccc}a&b&c\\d&e&f\\0&0&1\end{array}\right]](/~cs3421/latexrender/pictures/c3b736a2def4346c5cd918ff0af7c9c2.gif)
and solve for a,b,c,d,e,f.)
Question 4
Prove that we can transform a line by transforming its endpoints and then constructing a new line between the transformed endpoints. Can you do the same thing for circles by transforming the centre and a point on the circle?
Question 5
Complete the solution to finding the window to viewport transformation started in lectures.

![\left[\begin{array}{ccc}a&b&c\\d&e&f\\0&0&1\end{array}\right]
\left[\begin{array}{ccc}W_l&W_l&W_r\\W_t&W_b&W_b\\1&1&1\end{array}\right]=
\left[\begin{array}{ccc}V_l&V_l&V_r\\V_t&V_b&V_b\\1&1&1\end{array}\right]
\left[\begin{array}{ccc}a&b&c\\d&e&f\\0&0&1\end{array}\right]
\left[\begin{array}{ccc}W_l&W_l&W_r\\W_t&W_b&W_b\\1&1&1\end{array}\right]=
\left[\begin{array}{ccc}V_l&V_l&V_r\\V_t&V_b&V_b\\1&1&1\end{array}\right]](/~cs3421/latexrender/pictures/7049f1f52cfa8b53cd078e2b6d25aaa9.gif)