Download the App!
Get 24/7 study help with the Numerade app for iOS and Android! Enter your email for an invite.
Question
Answered step-by-step
Use the guidelines of this section to sketch the curve.$$y=x^{3}+3 x^{2}$$
Video Answer
Solved by verified expert
This problem has been solved!
Try Numerade free for 7 days
Like
Report
Official textbook answer
Video by Mary Wakumoto
Numerade Educator
This textbook answer is only visible when subscribed! Please subscribe to view the answer
12:21
Bobby Barnes
Calculus 1 / AB
Calculus 2 / BC
Chapter 4
Applications of Differentiation
Section 5
Summary of Curve Sketching
Derivatives
Differentiation
Volume
Campbell University
Harvey Mudd College
University of Michigan - Ann Arbor
Lectures
04:35
In mathematics, the volume of a solid object is the amount of three-dimensional space enclosed by the boundaries of the object. The volume of a solid of revolution (such as a sphere or cylinder) is calculated by multiplying the area of the base by the height of the solid.
06:14
A review is a form of evaluation, analysis, and judgment of a body of work, such as a book, movie, album, play, software application, video game, or scientific research. Reviews may be used to assess the value of a resource, or to provide a summary of the content of the resource, or to judge the importance of the resource.
12:25
Use the guidelines of this…
01:28
04:24
01:04
16:50
02:40
use the guidelines of this…
12:40
Okay here, we have a function Y equals execute plus three X squared. And we want to graph it, we know because it's cubic, it probably has some general shape like this. Um But let's go ahead and figure it out more. Specifically, I'm gonna go ahead and find the zeros first. I'm going to notice that experts in common leaving behind X plus three. So we know that we have zeros whenever X equals zero or Um X equals -3. So I'll go ahead and do those right away and that will give us some help with the graphing. And I can certainly just keep plotting points and I would be able to get the general shape of the graph. But let's use some derivatives. So let's keep going and find the first derivative. First derivative will be by power roll three X squared plus six X. I can factor out a three X. Giving me X plus two. And if I set that equal to zero, we find out that we have critical points at X equals zero And x equals -2. And so I'm going to go ahead and make a sign chart and keep it running so I can see what's happening. Okay, so at zero and at uh whoops, let's put the zero on the right since we need room for the -2. Okay, so we will put zero here minus two here, that's our X and our f prime of X is zero at both of these locations. Let's go ahead and plug in values to find out whether f prime of X is positive or negative in the different intervals if I plug in something bigger than zero, like one, I'll definitely get a positive. If I plug in -1 I will get a negative. If I plug in -3 I will get double negative. So that's a positive. Alright good. So basically I'm increasing decreasing, increasing. Alright now let's take a look at our next derivative. Let's do y double prime. That'll be six X plus six by power role. So pull out the six and I get X plus one And that equals zero when x equals -1. So let's plot that on our chart -1. That's the zero for f double prime. And let's again do the signs when you're bigger than -1, you definitely get a positive. Um So you get a positive positive and when you're um less than negative one then you get negative. And then this is how I can I really love doing the sign chart because this is how I can no the kind of general shapes. So I have Less than -2. I'm increasing concave down. So I've got this shape And between -2 and -1, I'm decreasing because I have a negative first derivative but I'm concave down. So decreasing concave down. So that would be like this Then -1 is zero, I'm decreasing. Um concave up and then at the last bit I'm increasing concave up so I get my general shapes which is cool and alright so let's find also like max and men we know max occurs when F prime goes from plus to minus, so this will be a max point and um this will be an end point. Um and then here's a point of inflection because that's when F double prime changes sign point of inflection. Okay, so let's get the actual points. The max occurs At -2, let's plug it back into the original. So it's four times one. So four, the min occurs at X equals zero. So it was like that and we get zero. Good to know that are a point of inflection occurs at -1. Let's plug that in. I think it's this 1 -3, so -2. So now we have um all sorts of points up, like and we double check, I did that right, If I plug in -1 I get -1 a plus three. So that's actually positive two. I was looking at the wrong thing. Okay so let's plug in those points and we'll be able to finish drawing our graph. Okay, so -2 for we have a point up here, We have a point at my a point of inflection and -12. So that's the point of inflection. So basically we know that we have this shape. Um then it um switches to concave up because we have so far we've done that shape and that shape. Now we're concave up decreasing and then we're going to be concave up increasing as we get past the men. So let's just plug in one point on the right side. How about plugging in one? We plug in one, we get four. So then that would be up here and we have I think that's sufficient. We have drawn our graph, no horizontal as some toads, no vertical ascent. Oh, it's just a nice wonderful cubic function. So anyway, that's a lot of fun. Hopefully it helped have a great day.
View More Answers From This Book
Find Another Textbook
05:00
'Consider the following q problem in continuous time:v[Ko] max(t)tz…
03:47
'The average height of females in the freshman class of a certain colle…
02:35
'Let X represent the number that occurs when 6-sided red die is tossed …
01:36
"According recent survey; 61% of moviegoers in the United States prefer…
01:13
'Lynell is a student at a large state college. She read magazine articl…
'ithe P-value is smaller than the level of significance then the resear…
02:57
'The U.S. Department of Agriculture claims that the mean annual cOnsump…
03:05
'( pts ) Let $ be the event that a randomly selected college student ha…
01:23
'Claim: The mean pulse rate (in beats per minute_ of adult males is equ…
01:54
'The recommended number of hours of sleep per night is 8 hours_ but eve…