... a and b are orthogonal, (perpendicular), or one of a and b are zero.26 1 2 1 22468 10 1 2Figure 1. 11: Plots of f(x) = p(x)/q(x). 1. 6 HintsHint 1. 1area = constant ×diameter2.Hint 1. 2A ... with vertices at (1, 1) , (4, 2), (3, 7) and (2, 3)?Hint, SolutionExercise 2.7What is the volume of the tetrahedron with vertices at (1, 1, 0), (3, 2, 1) , (2, 4, 1) and (1, 2, 5) ?Hint, SolutionExercise ... from 1 to n and are called free indices.Example 2 .1. 1 Consider the matrix equation: A · x = b. We can write out the matrix and vectors explicitly.a 11 ··· a1n.........an1···...