Using recursion find the largest element in an array using

Question

Problem

1. Using recursion, find the largest element in an array.

2. Using recursion, compute the sum of all values in an array.

3. Using recursion, compute the area of a polygon. Cut off a triangle and use the fact that a triangle with corners (x₁, y₁), (x₂, y₂), (x₃, y₃) has area |x₁y₂ + x₂y₃ + x₃y₁ - y₁x₂ - y₂x₃ - y₃x₁| / 2