Brissa's desk is 3 feet long. About how long is it in meters? use 1 foot = 0.305 meter

Tom wants to reach a second floor window on a house that is 20 feet above ground. If he must put the ladder at a 70 degree angle

LuckyWell [14K]

Assuming the house is parallel to the ground, your triangle is made up by the house, the ground, and the ladder. Using sin(x) = opposite/hypotenuse on the angle 70 degrees, you would have sin(70) = 20/x (because 20 is the side opposite of the angle connecting the ladder and the ground)
--> simplify sin(70) * x = 20 --> x = 20 / sin(70
--> substitute (and make sure your calculator in in degrees) x= 21. 284

7 0

4 years ago

Use >, <, or = to complete the statement.

nalin [4]

It should be |-10| < |11| which I think is option C?

6 0

3 years ago

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Two birds sit at the top of two different trees. The distance between the first bird and a birdwatcher on the ground is 29.7 fee

VladimirAG [237]

Answer:

44.87°

Step-by-step explanation:

5 0

3 years ago

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Marine biologists have determined that when a shark detectsthe presence of blood in the water, it will swim in the directionin w

siniylev [52]

Solution :

a). The level curves of the function :

$C(x,y) = e^{-(x^2+2y^2)/10^4}$

are actually the curves

$e^{-(x^2+2y^2)/10^4}=k$

where k is a positive constant.

The equation is equivalent to

$x^2+2y^2=K$

$\Rightarrow \frac{x^2}{(\sqrt K)^2}+\frac{y^2}{(\sqrt {K/2})^2}=1, \text{ where}\ K = -10^4 \ln k$

which is a family of ellipses.

We sketch the level curves for K =1,2,3 and 4.

If the shark always swim in the direction of maximum increase of blood concentration, its direction at any point would coincide with the gradient vector.

Then we know the shark's path is perpendicular to the level curves it intersects.

b). We have :

$\triangledown C= \frac{\partial C}{\partial x}i+\frac{\partial C}{\partial y}j$

$\Rightarrow \triangledown C =-\frac{2}{10^4}e^{-(x^2+2y^2)/10^4}(xi+2yj),$ and

$\triangledown C$ points in the direction of most rapid increase in concentration, which means $\triangledown C$ is tangent to the most rapid increase curve.