Please help!
Use a graphing calculator to determine all local maxima and/or minima for the function y = 2x^3 - 7x^2 - 4x. Give the values where the extremum occur to two decimal places.

Question

Please help!
Use a graphing calculator to determine all local maxima and/or minima for the function y = 2x^3 - 7x^2 - 4x. Give the values where the extremum occur to two decimal places.

anonymous · Answer

What kind of graphing calculator do you have?

anonymous · Answer

TI-84

anonymous · Answer

did you already plug the equation in to the y= portion and get a graph?

anonymous · Answer

yes

anonymous · Answer

ok do you see where the graph curves the 2 points? at one point it curves down and at the other it curves up?

anonymous · Answer

Yes

anonymous · Answer

I think...

anonymous · Answer

the curve with the highest value of y is the local max, the value with the smallest value of y is the local min. use the trace function on the calculator to get your answers.

anonymous · Answer

what did you come up with?

anonymous · Answer

Local max: -0.212766

anonymous · Answer

Local min: 2.5531915

anonymous · Answer

yes that's pretty close

anonymous · Answer

How do I find the exact number?

anonymous · Answer

that answer will work for using a graphing utility

anonymous · Answer

Local max: -0.257334
Local min: 2.59067

Is that closer?

anonymous · Answer

If it says two decimal places, would I round the local max up from -0.257 to -0.26?

anonymous · Answer

yes....also check this video http://www.youtube.com/watch?v=xTofCWXtYyU

anonymous · Answer

attachment

anonymous · Answer

those points are correct

anonymous · Answer

Dude! Thank you! This video is so insightful!

anonymous · Answer

No problem, hope it help! FYI you tube is an amazing resource

anonymous · Answer

So wait, one last question... so if it says only two decimal places, do I round -0.257 to -0.26, or do I just take -0.25?

anonymous · Answer

round up to -.26