## Final Answer

## Step-by-step Solution

Problem to solve:

Solving method

We can solve the integral $\int xe^{2x}dx$ by applying integration by parts method to calculate the integral of the product of two functions, using the following formula

The derivative of the linear function is equal to $1$

First, identify $u$ and calculate $du$

Now, identify $dv$ and calculate $v$

Solve the integral

We can solve the integral $\int e^{2x}dx$ by applying integration by substitution method (also called U-Substitution). First, we must identify a section within the integral with a new variable (let's call it $u$), which when substituted makes the integral easier. We see that $2x$ it's a good candidate for substitution. Let's define a variable $u$ and assign it to the choosen part

Differentiate both sides of the equation $u=2x$

Find the derivative

The derivative of the linear function times a constant, is equal to the constant

Now, in order to rewrite $dx$ in terms of $du$, we need to find the derivative of $u$. We need to calculate $du$, we can do that by deriving the equation above

Isolate $dx$ in the previous equation

Substituting $u$ and $dx$ in the integral and simplify

Divide $1$ by $2$

Take the constant $\frac{1}{2}$ out of the integral

The integral of the exponential function is given by the following formula $\displaystyle \int a^xdx=\frac{a^x}{\ln(a)}$, where $a > 0$ and $a \neq 1$

Replace $u$ with the value that we assigned to it in the beginning: $2x$

Multiply $1$ times $\frac{1}{2}$

The integral of a constant by a function is equal to the constant multiplied by the integral of the function

Now replace the values of $u$, $du$ and $v$ in the last formula

We can solve the integral $\int e^{2x}dx$ by applying integration by substitution method (also called U-Substitution). First, we must identify a section within the integral with a new variable (let's call it $u$), which when substituted makes the integral easier. We see that $2x$ it's a good candidate for substitution. Let's define a variable $u$ and assign it to the choosen part

Differentiate both sides of the equation $u=2x$

Find the derivative

The derivative of the linear function times a constant, is equal to the constant

Now, in order to rewrite $dx$ in terms of $du$, we need to find the derivative of $u$. We need to calculate $du$, we can do that by deriving the equation above

Isolate $dx$ in the previous equation

Substituting $u$ and $dx$ in the integral and simplify

Take the constant $\frac{1}{2}$ out of the integral

The integral of the exponential function is given by the following formula $\displaystyle \int a^xdx=\frac{a^x}{\ln(a)}$, where $a > 0$ and $a \neq 1$

Replace $u$ with the value that we assigned to it in the beginning: $2x$

The integral $-\frac{1}{2}\int\frac{e^u}{2}du$ results in: $-\frac{1}{4}e^{2x}$

Gather the results of all integrals

As the integral that we are solving is an indefinite integral, when we finish integrating we must add the constant of integration $C$