Talk:Calculus/Precalculus/Exercises

Removed problem 6 from "Functions" section
I removed the following problem from the "Functions" section (old problem 6):


 * 1) Consider the following function
 * $$f(x) = \frac{2x^2+2x+1}{x^2-1} $$
 * 1) What is the domain?
 * 2) What is the range?
 * 3) Where is $$f$$ continuous?

Subproblems 1 and 3 are simple enough, but I can't see any way to find the exact range without using calculus. The range seems to be all real numbers except for a gap from about -1.5 to 0.5. However, to find what the exact numbers are, it looks like you would have to find the local maximum and minimum in the vicinity of x=0. The usual way to do that requires calculus, and since this section is a review of precalculus, we can't assume the reader has that knowledge.

Greenbreen (discuss • contribs) 07:48, 16 March 2011 (UTC)

Some issues
I'm out of time to edit this page, but here are a few things I noticed. Greenbreen (discuss • contribs) 08:12, 3 April 2011 (UTC)
 * Problems 4-7 under the functions section ask about the continuity of the given function. This topic isn't covered until Calculus/Limits, so it seems out of place here.
 * I haven't analyzed it extensively, but problem 6 subproblem 2 under the functions section seems to have the same issue as I mentioned in an earlier topic on this discussion page. I hate to remove problems just because I can't see how they are intended to be done, but if there is a consensus that this is not an appropriate exercise for this section, then I'd go ahead and remove it.
 * The decomposition of functions section seems pointless as you could always choose g(x)=x, f(x)=h(x). In any case, the decomposition will not be unique.
 * I removed the "Decomposition of Functions" exercises for the reasons I mentioned above. --Greenbreen (discuss • contribs) 18:27, 22 May 2011 (UTC)

Question 23's answer should be 8 to the 13 ninths power and not 2 to the 13 ninths power.
Question 23's answer should be 8 to the 13 ninths power and not 2 to the 13 ninths power.216.19.41.41 (discuss) 21:34, 12 April 2012 (UTC)


 * Your correct, aside from meaning sixths instead of ninths? But the 8 can be further reduced to a 2, adjusting the power, which I went ahead and changed in the solution. Thenub314 (talk) 21:54, 12 April 2012 (UTC)

In the pdf version, problem 9 of 6.7.1 is incorrect
The pdf has problem 9 of exercise 6.7.1 (page 45) defined as "5<x and x<6". The answer key (page 407) later claims the solution to be "(-,5)", but the correct answer looks like the one in the html version; "(5,6)". Can someone run a new copy of the pdf to synchronize them? Chasetruck (discuss • contribs) 18:59, 26 April 2012 (UTC)

Answer 52. b.
I don't think the answer is correct as the question asks for both the domain and the range of x^2. The domain is (-∞,+∞) and the range is always positive therefore [0,+∞). The answer just gives the domain...

Also 53.b seems wrong, I think it is 5/2 not 1/4.

Graphing exercises
I'm not a math guru, but shouldn't the solutions to the graphing exercises be in slope-intercept form? If not, perhaps they should at least specify what form they should be in.

--ChrisBlueStone (discuss • contribs) 04:04, 29 May 2013 (UTC)

Exercise 44
I've been looking for the best part of the last hour but I can't seem to find anything about exercise 44 in the Algebra section of this book, since it doesn't really explain how to solve polynomials of the third degree at all. Doriphor (discuss • contribs) 20:11, 13 April 2015 (UTC)