Recent content by communitycoll

Homework Statement A car dealer sells a new car for $18,000. He also offers to sell the same car for monthly payments of $375.00 for five years. What monthly rate is this dealer charging?Homework Equations A = [R(1 - (1 + i))^-60] / i where A = the present value, R = the monthly payment, i =...

How do I find the angles in the triangle?

Homework Statement How do I find out the exact value of tan^-1 (1 / sqrt(3))? Homework Equations nada The Attempt at a Solution I don't know where to start.

Okay then. Yeah, I understand now. Thanks.

Homework Statement <Indefinite integral sign here>[r^2 -2r] / [r^3 - 3r^2 + 1]dr or the second example in the "Substitution" section here: http://people.clarkson.edu/~sfulton/ma132/parfrac.pdf Homework Equations nada. The Attempt at a Solution Nothing to really attempt, I just...

Ah, forget I asked anything. I understand what I did wrong. Thanks anyway.

I use chain rule on each of those logs; should I not?

I got ln(y) for ln(y), I'm not sure I understand the first question. The derivative of that I got: (1 / y)(y')

Homework Statement y = [2x + 1]^5 * [(x^4) - 3]^6Homework Equations I take the derivative of the natural log of both sides: (y' / y) = [(10 ln(2x + 1)^4) / (2x + 1)] + [(24x^3 ln(x^4 - 3)^5) / (x^4 - 3)] then I multiply both sides by the original function: y' = [((10 ln(2x + 1)^4) / (2x +...

Ah, never mind, I was thinking I'm meant to multiply the fraction in the denominator as if they were being added/subtracted, trying to multiply the numerators by the denominators of both the fraction and (1 + x)^2. I get it now. Thanks, I appreciate your patience : D

Tell me what to do next or what I've done wrong here: just showing the denominator: = 1 + 2x + x^2 + [(1 - 2x + x^2)(1 + 2x + x^2)(1 + 2x + x^2) / (1 + 2x + x^2)] = 1 + 2x + x^2 + (1 - 2x + x^2)(1 + 2x + x^2) = 1 + 2x + x^2 + 1 + 2x + x^2 - 2x - 4x^2 - 2x^3 + x^2 + 2x^3 + x^4 = 2 + x^4 -...

Homework Statement Find the derivative of arctan[(1 - x) / (1 + x)]. Homework Equations Everything in the "Show Steps" section: http://www.wolframalpha.com/input/?i=derivative+arctan%5B%281+-+x%29+%2F+%281+%2B+x%29%5D My problem is that I don't know how Wolfram manages to simplify...

Ah. I understand now. It took me a bit, but I understand now. Thanks.

But if -4x(x-1) is under a radical (as well as being multiplied) how is it that I pull a 2 out of that?

Ah terribly sorry. 2 / sqrt(1 - (2x + 1)^2); the last thing in the show steps part for the derivative in Wolfram.