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.
Up to 1 in 10 children with measles received a single dose of vaccination. This is to be expected, as a single dose of MMR vaccine protects only 9 in 10 children. That's why children need a second dose. After a second dose, 9 in 10 of those who didn't respond to the first dose will be protected â so the second dose boosts protection to almost 100%.