They do what they do.
Thinking about schools and peers and parent-child attachments....I came across one of my favorite posts .
Shouldn't it be "only 16% could solve for Y"?y=1-1 = 0
They mean solving for x as a function of y, and you should read that as y = x/(x-1). This is the kind of fraction that students have fits with, since they want to break up the denominator in creative ways.
This same professor, Cliff Mass, posted this same problem on youtube about three years ago.http://www.youtube.com/watch?v=ymvSFunUjx0He is a professor of Atmospheric Science at the University of Washington, and the video asks people to read wheresthemath.com and to reject the NCTM progressive math standards.I'm surprised the "cheaters network" hasn't told more people the answers to his little test (psst: 4b is its own inverse!).
OK, I'll try it. I assume "solve for x as a function of y" means "massage the equation until you have x on one side of the eqn, with only ys on the other side."We start here:y = x/(x-1)Multiply both sides by (x-1):y(x-1) = xWe're not happy yet because we have x on both sides of the eqn. We continue by simplifying:xy - y = xMove all x-related stuff to one side:-y = x - xyRewrite rhs:-y = x(1 - y)Now divide both sides by (1 - y):-y/(1-y) = xet voila!I'm reviewing math previous to teaching dd, so if I did that wrong, please let me know!
You're right; you just need to further simplify:[-y/(1-y)] * (-1/-1) = xy/(y-1) = x
Did I write that wrong?Probably.
hmmm... it says "solve for x"
Solve for x works if you put the parentheses in: y=x/(x-1)LSquared
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