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Find y if dy/dx=xe^x?

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mikok | Student, Undergraduate | eNoter

Posted August 10, 2011 at 8:20 PM via web

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Find y if dy/dx=xe^x?

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giorgiana1976 | College Teacher | Valedictorian

Posted August 10, 2011 at 8:28 PM (Answer #1)

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To determine the primitive function Y, we'll have to calculate the indefinite integral of the given function:

x*`e^(x)`dx = `int`dy = Y

We'll integrate by parts using the formula:

udv = uv - vdu

Let u = x => du = dx

Let dv = `e^(x)` dx => v = `e^(x)`

x*`e^(x)` dx = x*`e^(x)` - `int` `e^(x)` dx

 

x*`e^(x)`= x*`e^(x)`- `e^(x)`+ C

 

The requested primitive function is Y = (x-1)*`e^(x)` + C.

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giorgiana1976 | College Teacher | Valedictorian

Posted August 10, 2011 at 8:30 PM (Answer #2)

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There are missing some integral signs and I'll re-write the answer again:

`int` x*`e^(x)` dx = `int` dy = Y

We'll integrate by parts using the formula:

`int` udv = uv - `int` vdu

Let u = x => du = dx

Let dv = dx => v =

`int` x* dx = x* - dx

`int` x*dx = x*- + C

The requested primitive function is Y = (x-1)* + C.

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giorgiana1976 | College Teacher | Valedictorian

Posted August 10, 2011 at 9:00 PM (Answer #3)

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I'll try again to type correctly:

`int` x*`e^(x)` = `int` dy = Y

`int` x*`e^(x)` dx = x*`e^(x)` - `int` `e^(x)`

`int` x*`e^(x)` dx = `e^(x)`*(x - 1) + C

Therefore, the requested primitive function is Y = (x-1)*`e^(x)` + C.

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