Preview question: If n is an integer, n ∙ 180° represents an integer multiple of 180°, and 

Behaviour being used: Adaptive mode

Minimum fraction: 0

Question summary: If n is an integer, n ∙ 180° represents an integer multiple of 180°, and  represents an odd integer multiple of 90°. Decide whether the expression is equal to 0, 1, -1, or is undefined.  tan((2n + 1) ∙ 90°): -1; 0; 1; Undefined

Right answer summary: Undefined

Question state: todo