“A branch of applied mathematics that concerns itself with mathematical methods and techniques that are typically used in engineering and industry.” -?from Wikipedia(en)
“An interdisciplinary subject motivated by engineers needs both for practical, theoretical and other considerations outwith their specialization, and to deal with constraints to be effective in their work.”?-?from Wikipedia(en)
Reference
『Advanced Engineering Mathematics』 4th edition
by Dennis G. Zill and Warren S. Wright (Dec 21, 2009)