DVD+R DL (DL stands for Double Layer) also called DVD+R9, is a derivative of the DVD+R format created by the DVD+RW Alliance.Its use was first demonstrated in October 2003. DVD+R DL discs employ two recordable dye layers, each capable of storing nearly the 4.7 GB capacity of a single-layer disc, almost doubling the total disc capacity to 8.5 GB. Discs can be read in many DVD …

Mathematics. 9 is a composite number, its proper divisors being 1 and 3.It is 3 times 3 and hence the third square number.Nine is a Motzkin number. It is the first composite lucky number, along with the first composite odd number and only single-digit composite odd number.. 3 times 3 is one more than 2 times 2 times 2. Thus, 9 is a positive perfect power that is one more than …