Integral of a vector valued function

In summary, the conversation is discussing two possible formulas for isolating a vector valued function in an integral, but both are incorrect. The correct formula involves using integration by parts.
  • #1
Lucid Dreamer
25
0
I came across this integral of a vector valued function.
[tex] \int \mathbf A(t) \vec{w(t)} dt = \int \mathbf B(t) [/tex].
I want to isolate [itex] \vec{w(t)} [/itex] and so I multiply by [itex] \left (\int \mathbf A(t) dt \right)^{-1} [/itex] on both sides.
[tex] \left (\int \mathbf A(t) dt \right)^{-1} \int \mathbf A(t) \vec{w(t)} dt = \left (\int \mathbf A(t) dt\right)^{-1} \int \mathbf B(t) dt [/tex]

I thought the correct form would be
[tex] \int \vec{w(t)} dt = \left (\int \mathbf A(t) dt\right)^{-1} \int \mathbf B(t) dt [/tex].

But it turns out I get the right answer if I take
[tex] \vec{w(t)} = \left (\int \mathbf A(t) dt \right)^{-1} \int \mathbf B(t) dt [/tex].

Can anyone show why the second form is correct?
 
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  • #2
Both formulas are wrong. Check it with ##\omega(t)=t^2## and ##A(t)=e^t##. All we have is the integration by parts: ##\displaystyle{\int } A(t)\omega(t)dt = \left(\int A(t)dt\right) \omega(t) - \int \left(\int A(t)dt\right)\omega'(t)dt##
 

FAQ: Integral of a vector valued function

What is the definition of the integral of a vector valued function?

The integral of a vector valued function is a mathematical concept that represents the accumulation of the vector values over a specific interval. It is a generalization of the one-dimensional definite integral and is used to calculate quantities such as displacement, velocity, and acceleration in multi-dimensional spaces.

How is the integral of a vector valued function calculated?

The integral of a vector valued function is calculated by taking the limit of Riemann sums as the number of partitions of the interval approaches infinity. This involves breaking down the interval into smaller subintervals and approximating the vector values within each subinterval. The final result is a vector that represents the total accumulation of the vector values over the entire interval.

What is the significance of the integral of a vector valued function?

The integral of a vector valued function has a wide range of applications in physics, engineering, and other sciences. It is used to calculate important quantities such as work, momentum, and energy. In addition, it is also used to solve differential equations and determine the behavior of systems over time.

Can the integral of a vector valued function have a negative value?

Yes, the integral of a vector valued function can have a negative value. This is because the integral represents the net accumulation of the vector values, which can be positive, negative, or zero. In some cases, the integral may have a negative value when the vector values are alternating between positive and negative within the interval.

What are some common techniques used to solve integrals of vector valued functions?

Some common techniques used to solve integrals of vector valued functions include the fundamental theorem of calculus, substitution, integration by parts, and partial fractions. These techniques are used to simplify complex integrals and make them easier to evaluate. In addition, numerical methods such as Simpson's rule and Monte Carlo integration can also be used to approximate the integral.

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