Antiderivative math homework help

In summary, the integral of (2x^2+1)^7 cannot be solved using substitution and the most efficient method is to expand the polynomial and integrate each term separately. Alternatively, using a symbolic processor such as Maxima can provide the expanded form of the integral. The binomial theorem is a useful tool for expanding polynomials in this manner.
  • #1
Nope
100
0

Homework Statement



[tex]\int(2x^2+1)^7[/tex]

Homework Equations


The Attempt at a Solution


u=2x^2+1
du=4xdx
u7 (1/4x)du
I am stuck... I don't know what to do next...
 
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  • #2


Nope said:

Homework Statement



[tex]\int(2x^2+1)^7[/tex]
Try to remember to put in the differential...
Nope said:

Homework Equations





The Attempt at a Solution


u=2x^2+1
du=4xdx
u7 (1/4x)du
I am stuck... I don't know what to do next...
Substitution won't work in this case, which you already found out. If you expand [itex]\int(2x^2+1)^7[/itex], you'll get a polynomial that you can integrate pretty easily.
 
  • #3


wow, so i have to expand everything out? (2x^2+1)^7
that's a lot
is there any other way to do it?
 
  • #4


The x2 suggests a trig substitution might work.

Edit: Actually, that looks to be more of a pain than just multiplying the polynomial out.

Hint: Use the binomial theorem.
 
  • #5


Nope, I don't think so, at least no way that's not a lot more complicated.
 
  • #6


Nope said:
wow, so i have to expand everything out? (2x^2+1)^7
that's a lot
is there any other way to do it?

Is using a symbolic processor cheating? From Maxima ...

ratsimp((2*x^2+1)^7);

[tex]128\,{x}^{14}+448\,{x}^{12}+672\,{x}^{10}+560\,{x}^{8}+280\,{x}^{6}+84\,{x}^{4}+14\,{x}^{2}+1[/tex]
 
  • #7


Probably not, but will you have one available during a test?
 
  • #8


No , I don't think so.
 
  • #9


It does help to know the "binomial theorem":

[tex](a+ b)^n= \sum_{i=0}^n \begin{pmatrix}n \\ i\end{pmatrix}a^{i}b^{n-i}[/tex]
 

Related to Antiderivative math homework help

1. What is an antiderivative?

An antiderivative is the inverse operation of a derivative. It is a function that, when differentiated, gives the original function.

2. How do I find the antiderivative of a function?

To find the antiderivative of a function, you can use the reverse power rule, which states that the antiderivative of a polynomial is the polynomial with each term raised to the next higher power, divided by the new power.

3. Can I use the constant of integration when finding an antiderivative?

Yes, the constant of integration, denoted as "+ C", is always included when finding an antiderivative. This is because when differentiating, the constant will become 0, so it is important to include it in the antiderivative.

4. What is the relationship between the derivative and the antiderivative?

The derivative and antiderivative are inverse operations of each other. This means that the derivative of a function gives the slope of the tangent line at any given point, while the antiderivative gives the original function when differentiated.

5. Is there a shortcut for finding antiderivatives?

Yes, there are some common antiderivatives that you can memorize to make the process quicker. These include the antiderivatives of polynomial functions, exponential functions, and trigonometric functions, among others.

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