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3 years ago

8

Please help! need help figuring this question out

1 answer:

beks73 [17]3 years ago

4 0

The earth is a spherical object, and you're correct, its radius is 3959 miles.

we know 71% of that is covered in water, that means 29% of that is not, 71%+29% = 100%.

well, let's recall that whatever% of anything is just (whatever/100) * anything.

now, how many square miles is its surface anyway?

$\bf \textit{surface area of a sphere}\\\\
SA=4\pi r^2~~
\begin{cases}
r=radius\\
-----\\
r=3959
\end{cases}\implies SA=4\pi (3959)^2
\\\\\\
SA=62694724\pi$

since 71% is already covered with water, we only need the other 29% covered, what is 29% of 62694724π, well, is just (29/100) * 62694724π.

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find the component equation of the plane which is normal to the vector -2i+5j+k and which contains the point (-10;7;5).

maksim [4K]

Given:

A plane is normal to the vector = -2i+5j+k

It contains the point (-10,7,5).

To find:

The component equation of the plane.

Solution:

The equation of plane is

$a(x-x_0)+b(y-y_0)+c(z-z_0)=0$

Where, $(x_0,y_0,z_0)$ is the point on the plane and $\left< a,b,c\right>$ is normal vector.

Normal vector is -2i+5j+k and plane passes through (-10,7,5). So, the equation of the plane is

$-2(x-(-10))+5(y-7)+1(z-5)=0$

$-2(x+10)+5y-35+z-5=0$

$-2x-20+5y-35+z-5=0$

$-2x+5y+z-60=0$

$-2x+5y+z=60$

Therefore, the equation of the plane is $-2x+5y+z=60$ .

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2 years ago

Find the cost of 25 shares of stock at 11 1/4 per share

musickatia [10]

I believe the answer is 2.222222222

4 0

3 years ago

Can someone explain this to me

MA_775_DIABLO [31]

The answer is -4(3n+5)

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2 years ago

If the parent function f(x)= x^2 is modified to g(x)= 2x^2+1, which statement is true about g(x)?

adell [148]

Hello :
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3 0

2 years ago

Read 2 more answers

How is this worked out ? im confused.

Rudik [331]

Answer:

From the given ratio for $tan\theta=\frac{4}{5}$ we found the values are

$sin\theta=4$

$cos\theta=5$

$csc\theta=\frac{1}{4}$

$sec\theta=\frac{1}{5}$

$cot\theta=\frac{5}{4}}$

Step-by-step explanation:

Given the ratio for $tan\theta=\frac{4}{5}$

We have to find the rest of trignometric functions:

$tan\theta=\frac{4}{5}\hfill (1)$

$tan\theta$ can be written as

$tan\theta=\frac{sin\theta}{cos\theta}\hfill (2)$

Comparing equations (1) and (2) we get

$tan\theta=\frac{sin\theta}{cos\theta}=\frac{4}{5}$

$\frac{sin\theta}{cos\theta}=\frac{4}{5}$

Equating the coressponding numerator and denominator respectively

Therefore $sin\theta=4$ and $cos\theta=5$

We can find $csc\theta$

$csc\theta=\frac{1}{sin\theta}$

$=\frac{1}{4}$ (since $sin\theta=4$ )

$csc\theta=\frac{1}{4}$

We can find $sec\theta$

$sec\theta=\frac{1}{cos\theta}$

$=\frac{1}{5}$ (since $cos\theta=5$ )

$sec\theta=\frac{1}{5}$

To find $cot\theta$ :

$cot\theta=\frac{1}{tan\theta}$

$=\frac{1}{\frac{4}{5}}$

$=1\times \frac{5}{4}$

$=\frac{5}{4}}$

$cot\theta=\frac{5}{4}}$

7 0

3 years ago