Integration using substitution (1 Viewer)

cloud edwards

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Question: (refer to attachment), Evaluate the intergral using u=x^4 -3.

I did this question without subbing in the x=0 & x=1 and got a fairly reasonable answer being: 211/20. I also checked with a couple of online integration calculators.

HOWEVER,
I realized i was supposed to sub in the x values into u=x^4-3 to get the boundaries. But when i did this, i got a ridiculous number being: -174,000 something.

PLEASE HELP!!!
 

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InteGrand

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Question: (refer to attachment), Evaluate the intergral using u=x^4 -3.

I did this question without subbing in the x=0 & x=1 and got a fairly reasonable answer being: 211/20. I also checked with a couple of online integration calculators.

HOWEVER,
I realized i was supposed to sub in the x values into u=x^4-3 to get the boundaries. But when i did this, i got a ridiculous number being: -174,000 something.

PLEASE HELP!!!




 

Drongoski

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let u = x^4 - 3 when x=0 u = -3 when x = 1 u=-2

So in your substituted work, you have to change the limits of integration to -3 and -2 resp.

Or you can do it my way without substitution:

 
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