6 of 6 Items .... Type: Terminology

. . . View This Fullsize

Help me understand the fundamental definition of concavity.
Consider the function \(y = x^4 \)

Can we say that is concave up from \((-\infty, +\infty)\)
or do we need to say \( (-\infty,0) \cup(0,+\infty) \)?

Here is it, if you want to see a visual.

. . . View This Fullsize

Is money a discrete variable or a continuous one?

. . . View This Fullsize

Anybody else object to calling the y-intercept the "starting value"? Isn't it the "starting value" only **sometimes**? If the starting value is b, then what happens when x < 0???

What's your thinking on this?

What about in this case:

Our situation was looking at temperatures for skydivers-- it doesn't make sense that the skydivers would "start" their dive at 63.4 degrees, it only makes sense in context with consideration to the coordinate itself.

. . . View This Fullsize

Explain Marginal Tax Rates.

. . . View This Fullsize

This quadrilateral is poorly drawn but correctly marked. What is the best name for this quadrilateral?




A graphical look here.

An accurately drawn version:

. . . View This Fullsize

"I wish we had better notation for intervals. The fact that \( 3 < x < 7 \) is written as \( (3, 7) \) which looks identical to the coordinates of a point on the Cartesian plane is less than ideal. ~ Jim Doherty (@mrdardy)