by deathsta2 » January 9th, 2008, 11:32 pm
Hey,
I have quiz this Friday on using derivatives to analyze and develop graphs of functions by developing sign charts to assist in the analysis of functions.
Question: f(x)= cube root of (x^2+x+1)
Here's how far I got...
f'(x)=2/3x(x^2+x+1)^-1/3
f''(x)=2/3(x^2+x+1)^-1/3 + 2/3x(-1/3(x^2+x+1)^-4/3)
= ?
Can I simplify to 2/3(x^2+x+1)^-1/3 * (x^2+x+1) by factoring out 2/3(x^2+x+1)^-1/3
Then after applying the sign charts... I get wrong answers for (a) the maximum/minimum values, (b)the intervals on which f increasing,(c) the intervals on which f decreasing, (d) open intervals on which f is concave up,(e) open intervals on which f is concave down, (f) the x-coordinates of all inflection points.
I think I miscalculated the second derivative.
Hey,
I have quiz this Friday on using derivatives to analyze and develop graphs of functions by developing sign charts to assist in the analysis of functions.
Question: f(x)= cube root of (x^2+x+1)
Here's how far I got...
f'(x)=2/3x(x^2+x+1)^-1/3
f''(x)=2/3(x^2+x+1)^-1/3 + 2/3x(-1/3(x^2+x+1)^-4/3)
= ?
Can I simplify to 2/3(x^2+x+1)^-1/3 * (x^2+x+1) by factoring out 2/3(x^2+x+1)^-1/3
Then after applying the sign charts... I get wrong answers for (a) the maximum/minimum values, (b)the intervals on which f increasing,(c) the intervals on which f decreasing, (d) open intervals on which f is concave up,(e) open intervals on which f is concave down, (f) the x-coordinates of all inflection points.
I think I miscalculated the second derivative.