Sums and differences are the results obtained by applying the operations of addition and subtraction, respectively, to particular mathematical objects. For the sake of clarity, the discussion is divided into two parts, with sums examined first,...

In mathematics, a difference operator maps a function, f(x), to another function, f(x + a) − f(x + b). The forward difference...

Research relating cognitive development to gender has been rather limited. The few studies that have explored such a relationship have been conclusive. The object of this study was to explore whether African students' performance on formal operations measure would be related to whether they...

Sales & Marketing The typical traveler may never even notice the operational differences between a timeshare resort and a hotel. But the insider knows that there are clear distinctions and sound business reasons why the daily operations differ. John Small, senior...

Internet icons Google Inc. and Yahoo Inc. are intensifying their efforts to become more accessible on mobile phones, a platform widely seen as the next big battleground for the longtime rivals.The Silicon Valley foes underscored their commitments to the mobile market Monday at the International...

An al-Qaida-affilated organization posted an online video Saturday of the execution-style shooting of 18 Iraqi security troops kneeling on the ground near a citrus grove.The three-minute video, on a Web site previously used by the Islamic State of Iraq, claimed the 18 kidnapped government security...