Whoever could do that would be (imo) an absolute legend!!!!

http://i2.photobucket.com/albums/y17/Nath015/Math2.jpg

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- June 28th 2006, 11:21 PMIskariusAnyone smarter than me! You're needed!
Whoever could do that would be (imo) an absolute legend!!!!

http://i2.photobucket.com/albums/y17/Nath015/Math2.jpg - June 29th 2006, 09:19 AMJameson
Mmmk. This is way too much for me personally to give you all the answers. Some other members might, but I'll get you started.

For #1 I am confused on some notation. Is it or ?

Either way, for A)i. plug in D(0). For ii. and iii. take the derivative of the function to get the max/min values. - June 29th 2006, 09:29 AMearbothQuote:

Originally Posted by**Iskarius**

I presume that you mean:

to Aii), iii) The values of the Cosine-function are between -1 and 1. Therefore the depth can only between 2 m and 8 m.

I've attached a diagram to do F).

Bye

EB - June 29th 2006, 01:49 PMSoroban
Hello, Iskarius!

Quote:

A jet of water in a backyard is of parabolic shape.

It starts 3 metres above the ground and just passes over the top of a tree

that is 5 metres high and is a distance of 2 metres horizontally from the starting point.

The jet of water strikes the surface of a flower bed at ground level

at a distance of 8 metres horizontally from the starting point.

A) Which of the following equations (in which a, b, c are constants) models the jet of water?

Since are cubic functions and is a straight line,

. . the answer is the only quadratic: .

Quote:

B) Use answer from part A to determine the values of a, b, and c.

Hence, state the equation of the path traced out by the jet of water.

Code:`| *`

(0,5)o *

* | *

* | *

(-2,3)o | *

| |

--+-----+--------------o--

-2 0 (6,0)

Since is on the graph, we have:

. .

The function (so far) is: .

Since is on the graph, we have:

. .

Since is on the graph, we have:

. .

Solve this system of equation and we get: .

Therefore, the equation is: .

Quote:

C) Find out how far the jet of water rises above the ground.

The vertex of the parabola is at: .

Our parabola has:

Its vertex is at: .

Therefore, the maximum height is:

. . metres.

Quote:

D) Find the angle of the jet to the horizontal at the starting point.

The derivative is: .

At , the slope of the tangent line is: .

Therefore: .