What are cross sections in calculus?

What does cross-section mean in calculus?

A cross section of a solid is a plane figure obtained by the intersection of that solid with a plane. The cross section of an object therefore represents an infinitesimal “slice” of a solid, and may be different depending on the orientation of the slicing plane.

How do you do a cross-section in calculus?

Video quote: If it's in terms of y then the cross sections has to be perpendicular to the y axis. So for this problem the cross sections are perpendicular to the x-axis.

What is a cross-section of a function?

Cross-Sections of the Graph of a Function. For a function f(x, y), the function we get by holding x fixed and letting y vary is called a cross-section of f with x fixed. The graph of the cross-section of f(x, y) with x = c is the curve, or cross-section, we get by intersecting the graph of f(x, y) with the plane x = c.

What is cross-section in simple terms?

Definition of cross section



1a : a cutting or piece of something cut off at right angles to an axis also : a representation of such a cutting. b : section sense 3b. 2 : a measure of the probability of an encounter between particles such as will result in a specified effect (such as scattering or capture)

What is a cross section of rock?

A cross section or cross-section, in geology, is a diagram representing the geologic features intersecting a vertical plane, and is used to illustrate an area’s structure and stratigraphy that would otherwise be hidden underground.

What is cross section in survey?

Cross-sectional surveys provide a snapshot of a population’s characteristics and what is happening at any one moment in time. They can be population-based by carrying out household surveys through random sampling or they can be conducted with health services and schools.

What is cross-section and longitudinal section?

Longitudinal studies and cross-sectional studies are two different types of research design. In a cross-sectional study you collect data from a population at a specific point in time; in a longitudinal study you repeatedly collect data from the same sample over an extended period of time.

What is the difference between profile Levelling and cross sectioning?

There is really no difference in procedure between profile and cross-section leveling except for the form of the field notes. Cross-section rod shots are usually taken during the route profile survey from the same instrument positions used to take rod shots along the centerline.

Why are cross-sectional studies used?

Cross-sectional studies are used to assess the burden of disease or health needs of a population and are particularly useful in informing the planning and allocation of health resources. A cross-sectional survey may be purely descriptive and used to assess the burden of a particular disease in a defined population.

What are the variables in a cross-sectional study?

Study different variables at the same time



Cross-sectional studies examine a population and draw conclusions from that group. This means that researchers can analyze that group and study different variables at the same time. Variables of a population could include gender, age, income or level of education.

What is cross-sectional data examples?

Cross-sectional data refer to observations of many different individuals (subjects, objects) at a given time, each observation belonging to a different individual. A simple example of cross-sectional data is the gross annual income for each of 1000 randomly chosen households in New York City for the year 2000.

What is the difference between cross-sectional and longitudinal studies?

Longitudinal studies differ from one-off, or cross-sectional, studies. The main difference is that cross-sectional studies interview a fresh sample of people each time they are carried out, whereas longitudinal studies follow the same sample of people over time.

Is cross-sectional data primary or secondary?

secondary analysis

However, in modern epidemiology it may be impossible to survey the entire population of interest, so cross-sectional studies often involve secondary analysis of data collected for another purpose. In many such cases, no individual records are available to the researcher, and group-level information must be used.

Is cross-sectional or longitudinal better?

longitudinal study

The benefit of a cross-sectional study design is that it allows researchers to compare many different variables at the same time. In a longitudinal study, researchers conduct several observations of the same test subjects over a period of time that could last many years.

Can a study be both cross-sectional and longitudinal?

The simplest longitudinal descriptive study consists of two repeated cross-sectional studies on the same population or samples, looking for the same measurements. Yes – repeated cross-sectional analysis can be longitudinal as you are repeatedly measuring something.

Is cross-sectional study quantitative or qualitative?

quantitative

Most cross-sectional studies are quantitative. They gather data through interviews, questionnaires, and focus groups over a certain period in time which may be in the past or the present, and then analyze the results.

When we try to explain the relationship among variables the study is called?

Correlational studies are used to show the relationship between two variables. Unlike experimental studies, however, correlational studies can only show that two variables are related—they cannot determine causation (which variable causes a change in the other).

How do we know if there is a relationship between two or more variables?

Regression. Regression analysis is used to determine if a relationship exists between two variables. To do this a line is created that best fits a set of data pairs. We will use linear regression which seeks a line with equation that “best fits” the data.

Is Grounded Theory a methodology?

Grounded theory is a well-known methodology employed in many research studies. Qualitative and quantitative data generation techniques can be used in a grounded theory study. Grounded theory sets out to discover or construct theory from data, systematically obtained and analysed using comparative analysis.

How variable is handled or manipulated?

The manipulated or independent variable is the one that you control. The controlled variable is the one that you keep constant. The responding variable or variables is what happens as a result of the experiment (i.e. it’s the output variable).

Is a placebo a dependent variable?

When a researcher gives an active medication to one group of people and a placebo, or inactive medication, to another group of people, the independent variable is the medication treatment. Each person’s response to the active medication or placebo is called the dependent variable.