PLS help ASAP I’d appreciate it, i have no idea how to do this

Mathematics

1 answer:

Korvikt [17]2 years ago

3 0

The correct answer is D.

The symbol you are looking at is sigma, which means sum of all. Because the number on the bottom is 1 and the top is 6, these are the start and end numbers for our n value. Therefore, it means to add together all of the values of your expression (n -3), for all of the values with n equaling between 1 and 6. So let's plug in all of the numbers for n they ask for and see what we have.

1 - 3 = -2

2 - 3 = -1

3 - 3 = 0

4 - 3 = 1

5 - 3 = 2

6 - 3 = 3

Now, when we add all of these numbers up, we look for the answer.

-2 + -1 + 0 + 1 + 2 + 3 = 3

This is the answer we see in D

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Am i correct? calculus

Advocard [28]

Check the picture below.

now, the "x" is a constant, the rocket is going up, so "y" is changing and so is the angle, but "x" is always just 15 feet from the observer. That matters because the derivative of a constant is zero.

now, those are the values when the rocket is 30 feet up above.

$\bf tan(\theta )=\cfrac{y}{x}\implies tan(\theta )=\cfrac{y}{15}\implies tan(\theta )=\cfrac{1}{15}\cdot y
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\stackrel{chain~rule}{sec^2(\theta )\cfrac{d\theta }{dt}}=\cfrac{1}{15}\cdot \cfrac{dy}{dt}\implies \cfrac{1}{cos^2(\theta )}\cdot\cfrac{d\theta }{dt}=\cfrac{1}{15}\cdot \cfrac{dy}{dt}
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\boxed{\cfrac{d\theta }{dt}=\cfrac{cos^2(\theta )\frac{dy}{dt}}{15}}\\\\
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$\bf cos(\theta )=\cfrac{adjacent}{hypotenuse}\implies cos(\theta )=\cfrac{15}{15\sqrt{5}}\implies cos(\theta )=\cfrac{1}{\sqrt{5}}\\\\
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\cfrac{d\theta }{dt}=\cfrac{11}{75}$