# Write a function equation

Functions algebra Video transcript For a given input value b, the function f outputs a value a to satisfy the following equation 4a plus 7b is equal to negative So for a given input b, the function f, the function f will output an a that satisfies this relationship right over here for the a and the b. Due to the nature of the mathematics on this site it is best views in landscape mode. If your device is not in landscape mode many of the equations will run off the side of your device should be able to scroll to see them and some of the menu items will be cut off due to the narrow screen width.

We are going to give several forms of the heat equation for reference purposes, but we will only be really solving one of them. Note that with this assumption the actual shape of the cross section i. Note that the 1-D assumption is actually not all that bad of an assumption as it might seem at first glance.

If we assume that the lateral surface of the bar is perfectly insulated i. This means that heat can only flow from left to right or right to left and thus creating a 1-D temperature distribution. The assumption of the lateral surfaces being perfectly insulated is of course impossible, but it is possible to put enough insulation on the lateral surfaces that there will be very little heat flow through them and so, at least for a time, we can consider the lateral surfaces to be perfectly insulated.

As indicated we are going to assume, at least initially, that the specific heat may not be uniform throughout the bar.

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Note as well that in practice the specific heat depends upon the temperature. As noted the thermal conductivity can vary with the location in the bar. Also, much like the specific heat the thermal conductivity can vary with temperature, but we will assume that the total temperature change is not so great that this will be an issue and so we will assume for the purposes here that the thermal conductivity will not vary with temperature.

First, we know that if the temperature in a region is constant, i. Next, we know that if there is a temperature difference in a region we know the heat will flow from the hot portion to the cold portion of the region. For example, if it is hotter to the right then we know that the heat should flow to the left.

Finally, the greater the temperature difference in a region i. In this case we generally say that the material in the bar is uniform.

There are four of them that are fairly common boundary conditions. The first type of boundary conditions that we can have would be the prescribed temperature boundary conditions, also called Dirichlet conditions.

These are usually used when the bar is in a moving fluid and note we can consider air to be a fluid for this purpose. Here are the equations for this kind of boundary condition. Note that the two conditions do vary slightly depending on which boundary we are at. If the heat flow is negative then we need to have a minus sign on the right side of the equation to make sure that it has the proper sign.

Note that we are not actually going to be looking at any of these kinds of boundary conditions here. These types of boundary conditions tend to lead to boundary value problems such as Example 5 in the Eigenvalues and Eigenfunctions section of the previous chapter.

It is important to note at this point that we can also mix and match these boundary conditions so to speak. This warning is more important that it might seem at this point because once we get into solving the heat equation we are going to have the same kind of condition on each end to simplify the problem somewhat.

We will now close out this section with a quick look at the 2-D and 3-D version of the heat equation. However, before we jump into that we need to introduce a little bit of notation first. The del operator also allows us to quickly write down the divergence of a function.

Okay, we can now look into the 2-D and 3-D version of the heat equation and where ever the del operator and or Laplacian appears assume that it is the appropriate dimensional version.where is assumed to be a real function and represents the potential energy of the system (a complex function will act as a source or sink for probability, as shown in Merzbacher [], problem ).

Wave Mechanics is the branch of quantum mechanics with equation as its dynamical leslutinsduphoenix.com that equation does not yet account for spin or relativistic effects.

Another special type of linear function is the Constant Function it is a horizontal line: f(x) = C No matter what value of "x", f(x) is always equal to some constant value. Jul 24,  · To write an exponential function given a rate and an initial value, start by determining the initial value and the rate of interest.

For example if a bank account was opened with \$ at an annual interest rate of 3%, the initial value is and the rate is%(1). Free quadratic equation calculator - Solve quadratic equations using factoring, complete the square and the quadratic formula step-by-step.

## 4 Ways to Insert Equations in Microsoft Word - wikiHow

Functions and equations Here is a list of all of the skills that cover functions and equations! These skills are organized by grade, and you can move your mouse over any skill name to preview the skill.

D.8 Write the equation of a linear function; D.9 Linear functions over unit intervals; D Average rate of change; E.1 Is (x, y) a.

I think this pretty well sums up divergence, at least as far as we will need to know for Maxwell's Equations. Remember: for any point in space, the divergence takes a vector function .

Obtaining a function from an equation (video) | Khan Academy