Big Education Ape: NY State backs down on inverse flub; no geometry gaffes until later today

Thursday, June 23, 2011

NY State backs down on inverse flub; no geometry gaffes until later today « JD2718

NY State backs down on inverse flub; no geometry gaffes until later today

by jd2718

New York State asked high school students to find the inverse function of a non-invertible function. 32. If $f(x) = x^2 - 6$ find $f^{-1}(x)$ . Youch. Teachers across the state yelled and screamed, but most importantly called the testing hotline (I never got through, all busy). What was the response?

They backed down. But tried to weasel out and claim they had not made an error. Here is the language in theirclarification memo:

“Because of variations in the use of $f^{-1}$ notation throughout New York State, a revised rubric for Question 32 has been provided. Please rescore all students’ responses to Question 32….” And then they allow $\pm\sqrt{x+6}$ or $\sqrt{x+6}$ or $-\sqrt{x+6}$ or “An explanation stating that the original function is not one-to-one and therefore there is no inverse”