Take a picture of the problem and then ask your question
<h3>4
Answers: A, B, C, D</h3>
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Explanation:
f(x) is continuous when x >= 1. The only discontinuity for f(x) is when x = 0, but 0 is not part of this interval.
f(x) is positive for any valid x value in the domain since x^6 is always positive. In general, x^n is positive for all x when n is any even number.
f(x) is decreasing. You can see this through a table of values or through a graph. For anything in the form 1/(x^k), it will be a decreasing function because x^k gets larger, so 1/(x^k) gets smaller, when x goes to infinity.
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The conditions to use the integral test have been met. So we have to see if
converges or not.
Let's integrate and find out

So we have

Meaning that,

If we plug in a = 1 and apply the limit as b approaches positive infinity, then the expression
will turn into 
Therefore,

Because this integral converges, this means the series
also converges as well by the integral test.
Natural numbers: Counting things! You look around your room and see an electronic device, then another, then another! You just counted to 3 using the natural numbers.
Whole numbers! You try to look for electronic devices and realise that they’re all gone. You have zero electronic devices, and you just used whole numbers.
You go online to find where your electronic devices went, and realise they were taken because you’re in debt to the bank so they took some of your stuff. You’re in negative numbers, and now you’ve used integers.
Eight cubes is written as 8^3
This means you multiply 8 by itself 3 times:
8 x 8 x 8 = 512