A binary operation, (Delta), is defined on the set of real numbers by (a Delta b = a + b + 4). Find the identity element.
-
A.
4 -
B.
2 -
C.
(frac{1}{4}) -
D.
-4
Correct Answer: Option D
Explanation
(a Delta b = a + b + 4)
(a Delta e = a + e + 4 = a)
(e = a – a – 4 = -4)