S smileykd New member Joined Sep 27, 2006 Messages 11 Oct 3, 2006 #1 Find the critical values, the interals where f(x) is increasing, the intervals where f(x) is decreasing, and the local extrema. f(x) = (9/x) + x
Find the critical values, the interals where f(x) is increasing, the intervals where f(x) is decreasing, and the local extrema. f(x) = (9/x) + x
tkhunny Moderator Staff member Joined Apr 12, 2005 Messages 11,325 Oct 3, 2006 #2 Have you considered the first derivative?
S smileykd New member Joined Sep 27, 2006 Messages 11 Oct 3, 2006 #3 How would the +x fit in when I use the quotient rule for 9/x?
G galactus Super Moderator Staff member Joined Sep 28, 2005 Messages 7,203 Oct 4, 2006 #4 smileykd said: How would the +x fit in when I use the quotient rule for 9/x? Click to expand... For heaven's sake, he means for 9/x. You know the derivative of x is 1?. You could even use the product rule, \(\displaystyle 9x^{-1}\)
smileykd said: How would the +x fit in when I use the quotient rule for 9/x? Click to expand... For heaven's sake, he means for 9/x. You know the derivative of x is 1?. You could even use the product rule, \(\displaystyle 9x^{-1}\)
tkhunny Moderator Staff member Joined Apr 12, 2005 Messages 11,325 Oct 4, 2006 #5 One piece at a time. If you are really bent on using the Quotient Rule ONLY, you can add the fraction. \(\displaystyle \L\,\frac{1}{x}+x\,=\,\frac{1+x^{2}}{x}\) It is important not to forget everything you learned in algebra.
One piece at a time. If you are really bent on using the Quotient Rule ONLY, you can add the fraction. \(\displaystyle \L\,\frac{1}{x}+x\,=\,\frac{1+x^{2}}{x}\) It is important not to forget everything you learned in algebra.
