Vector Fields in Maple. A vector field is described by a function that takes each point of the plane to a vector. > with(linalg): > F := (x,y) -> [-y,x]; We can evaluate this function at a point by plugging in values for x and y , just like we do with functions whose values are scalars.
The survey of U.S. parents finds that out of children participating in Fall and Winter sports, just 60 percent are wearing mouth guards. Taking a closer look at mouth guard usage for some higher-impact sports, the survey shows that for football, just 32 percent of parents report their child wears a mouth guard, for field hockey, just 14 percent. Lacrosse and ice hockey both fall at 11 percent, alongside volleyball. The complete list can be found here.
91 percent of kids are gamers, research says. The population of children who play video games is growing, and has been boosted in large part by kids between the ages of 2 and 5. An overwhelming number of American children between the ages of 2 and 17 are playing video games, a new study released today by the NPD Group has found. According to the research firm, 91 percent of kids between 2 and 17, or about 64 million people, are playing video games, up 9 percentage points compared to 2009.