Mathematics

Recent Answers

2009-11-21 Basic Math - Weighted Average:

Hi Dennis, There are many ways to compute the weighted average. Basically, the only mathematical requirement is that the weights all add up to one. I can say that the equation you gave is proper, since

2009-11-21 Calculus - Lim sin x/x:

Lim x→0 {(sinx°)/x} =? ANSWER: Questioner: akkha Country: Nepal Category: Calculus Private: No Subject: mathmetical problem Question: sir I have a mathmetical problem in limit and

2009-11-21 Advanced Math - Logarithm and exponent properties.:

Questioner: Brad Country: United States Category: Advanced Math Private: No Subject: Helping daughter with log problem Question: The problem is "Rewrite each expression as a sum or difference

2009-11-21 Word Problems - Percentages:

Taje $x abd invest it at 2%. That leaves $(3000-x) to be invested at 5%. The equation to solve is $x(2%) + $(3000-x)(5%) = $(3000)(4%). This mulitplies out to 0.02x + 150 - 0.05x = 120. Combine

2009-11-20 Calculus - Derivatives:

It can be said that f²(x) = x^2 + 1, so take the derivative. This gives 2f(x)f'(x) = 2x. Solve for f'(x) and get f'(x) = x/f(x). f"(x) = (f(x) - xf'(x))/f^2(x), and at this point I'll drop the x's