The following figure is converted into a cube. Its four positions (1), (2), (3), and (4) are shown. On the basis of these select correct altenative :-
In the figure shown, ABCD is a parallelogram. It is divided into triangles in such a way that ∠BEC=∠BCE. Which one of the following is correct?
Only 2
1, 2, 3
Only 1
Only 3
Which of the following are correct?
(1) cot(A+B) = cotAcotB−1cotA+cotB
(2) cot(A-B) = cotAcotB−1cotA−cotB
(3) tan(A+B) = tanA+tanB1−tanAtanB
(4) tan(A-B) = tanA−tanB1−tanAtanB