- #1
nameVoid
- 241
- 0
[tex]
\int x^3cos(x^2)dx
[/tex]
[tex]
-\frac{1}{2}x^2sin(x^2)+\frac{3}{2}\int xsin(x^2)dx
[/tex]
[tex]
-\frac{1}{2}x^2sin(x^2)+\frac{3}{4}cos(x^2)-\frac{3}{4}\int \frac{cos(x^2)}{x}
[/tex]
Last edited:
In your integration by parts, you don't show u and dv, etc., but you seem to be mostly on the right track.nameVoid said:the last integral
[tex]
\int x^3cos(x^2)dx
[/tex]
[tex]
-\frac{1}{2}x^2sin(x^2)+\frac{3}{2}\int xsin(x^2)dx
[/tex]
[tex]
-\frac{1}{2}x^2sin(x^2)+\frac{3}{4}cos(x^2)-\frac{3}{4}\int \frac{cos(x^2)}{x}
[/tex]
nameVoid said:the last integral
[tex]
\int x^3cos(x^2)dx
[/tex]
[tex]
-\frac{1}{2}x^2sin(x^2)+\frac{3}{2}\int xsin(x^2)dx
[/tex]
[tex]
-\frac{1}{2}x^2sin(x^2)+\frac{3}{4}cos(x^2)-\frac{3}{4}\int \frac{cos(x^2)}{x}
[/tex]
Integration by Parts is a method used to find the integral of a product of two functions, by using the product rule for differentiation in reverse. It is often used when the integral cannot be evaluated using other methods, such as substitution or the fundamental theorem of calculus.
The integration by parts formula is given by ∫ u dv = uv - ∫ v du, where u and v are two functions and dv and du are their respective differentials. This formula allows us to rewrite the original integral as a simpler one, and often leads to a solution that can be easily evaluated.
Integration by Parts is useful when the integral involves a product of two functions, and other methods such as substitution or the fundamental theorem of calculus cannot be applied. It is also helpful when the integral involves a function that can be easily differentiated, but not easily integrated.
The steps to use Integration by Parts are:
1. Identify the u and dv in the integral
2. Use the integration by parts formula to rewrite the integral
3. Integrate the simpler integral on the right side
4. Simplify the resulting integral
5. If possible, solve for the original integral
6. If not possible, repeat the process until the integral is solvable.
One helpful tip for using Integration by Parts is to choose u and dv in a way that will simplify the integral on the right side as much as possible. This will often lead to easier integrals that can be evaluated. Another tip is to keep track of the signs and constants when applying the formula, to avoid any errors in the final solution.