Write a function determinant_2x2(matrix) that computes the determinant of a 2×2 matrix.
**Formula:** For matrix [[a, b], [c, d]], det = a*d - b*c
Example:
Input: matrix = [[4, 6], [3, 8]]
Output: 14
**Explanation:** 4*8 - 6*3 = 32 - 18 = 14
Constraints:
Test Cases
Test Case 1
Input:
[[4, 6], [3, 8]]Expected:
14Test Case 2
Input:
[[1, 0], [0, 1]]Expected:
1Test Case 3
Input:
[[2, 3], [4, 6]]Expected:
0+ 2 hidden test cases