`int_2^8 1/((x-6)^3) dx = -1/(2(x-6)^2)|_2^8 = -1/2(1/(2^2) - 1/(-4)^2)=-1/2(1/4 - 1/16) `
`= -1/2(3/16) = -3/32`
The integral converges to a value of -3/32
Since the problem requests to decide if the given integral converges or diverges, then the upper limit must be `oo` and not 8.
Hence, you should evaluate the following limit to check if the integral converges or diverges, such that:
`int_2^oo 1/((x-6)^3)dx = lim_(n->oo) int_2^n 1/((x-6)^3)dx`
You may evaluate the integral `int 1/((x-6)^3)dx` using the following substitution such that:
`x-6 = t => dx = dt`
Changing the variable yields:
`int 1/((x-6)^3)dx= int 1/(t^3)dt`
Using the property of negative power yields:
`int 1/(t^3)dt = int (t^(-3))dt = t^(-3+1)/(-3+1) + c`
`int 1/(t^3)dt = int (t^(-3))dt = -1/(2t^2) + c`
Substituting back `x-6` for t yields:
`int 1/((x-6)^3)dx=-1/(2(x-6)^2) + c `
You may evaluate the definite integral using the fundamental theorem of calculus such that:
`int_2^n 1/((x-6)^3)dx = (-1/(2(x-6)^2))|_2^n`
`int_2^n 1/((x-6)^3)dx =-1/(2(n-6)^2) +1/(2(2-6)^2)`
`int_2^n 1/((x-6)^3)dx = 1/32 - 1/(2(n-6)^2)`
Evaluating the limit yields:
`lim_(n->oo) int_2^n 1/((x-6)^3)dx = lim_(n->oo)(1/32 - 1/(2(n-6)^2))`
`lim_(n->oo) int_2^n 1/((x-6)^3)dx = lim_(n->oo)(1/32) - lim_(n->oo) 1/(2(n-6)^2))`
`lim_(n->oo) int_2^n 1/((x-6)^3)dx =1/32 - (1/2)lim_(n->oo) 1/(n^2(1 - 6/n)^2)`
`lim_(n->oo) int_2^n 1/((x-6)^3)dx = 1/32 - (1/2)*(1/oo)`
`lim_(n->oo) int_2^n 1/((x-6)^3)dx = 1/32 - (1/2)*(0)`
`lim_(n->oo) int_2^n 1/((x-6)^3)dx = 1/32`
Hence, evaluating the improper integral yields `int_2^oo 1/((x-6)^3)dx = lim_(n->oo) int_2^n 1/((x-6)^3)dx = 1/32` , thus, the intgeral converges.
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