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#1 2021-02-24 12:27:24

jadewest
Member
Registered: 2021-02-20
Posts: 44

The Cartesian Coordinate System and the Distance Formula

Hello,
I am having trouble with two exercises related to this subject.

The first one states:

4.

What shape do these four points make? (Draw from one to the next in the order given,
and then draw from the last back to the first).

(0,-1), (0,3), (1,1), (-1,1)

A. A square
B. Two acute angles that meet at the acute angles
C. A triangle
D. Two right triangles that meet at the right angles
E. A rhombus
F. Two obtuse triangles that meet at the hypotenuse

My problem is that the figure that comes out is a rhombus, which is the same figure for exercise 3. I am getting confused in whether I'm right or not.





The second exercise is:

Find the distance between the two points:
14. (9, 0) and (-3, -8)

A. 4
B. √(61)
C. √(290)
D. 4[√(13)]
E. 5[√(17)]
F. 3[√(180)]

This is what I've done:
distance = sqrt (-3-9)^2 + (-8-0)^2
d = sqrt (-12)^2 + (-8)^2
d = sqrt 144+64
d = sqrt 208

The problem is that my result is not an alternative.

Thank you in advance!!!

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#2 2021-02-24 18:13:23

gustavowoltmann
Member
Registered: 2021-02-23
Posts: 1

Re: The Cartesian Coordinate System and the Distance Formula

Oh its very interesting article, Form starting i love math subject. If you have need so i can give good information about math subjects. Gustavo Woltmann

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#3 2021-02-24 20:35:44

Bob
Administrator
Registered: 2010-06-20
Posts: 10,053

Re: The Cartesian Coordinate System and the Distance Formula

hi jadewest

Q4.  If you just plot these four points, then they do seem to make a rhombus, but the questions says join them in order.  The lines joining (0,-1) to (0,3) and (1,1) to ( -1,1) cross over so rhombus is not the answer.

Q14.  Your working is correct but there is one more step you can make.

√ 208 = √ (16x13) = √ 16 x √ 13.

So you have found an answer they is one of the ones given.

Bob


Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob smile

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#4 2021-02-25 05:19:20

jadewest
Member
Registered: 2021-02-20
Posts: 44

Re: The Cartesian Coordinate System and the Distance Formula

Hi Bob,
So the right answer for Q14 would be the 4 * sqrt 13, or alternative D.

I'm sorry, but I'm still confused in Q4. Even if I put them in the order given in the exercise, the figure that comes out is a rhombus. I'm not sure what exactly I'm doing wrong.

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#5 2021-02-25 06:35:58

jadewest
Member
Registered: 2021-02-20
Posts: 44

Re: The Cartesian Coordinate System and the Distance Formula

I think I finally got Q4!!! In the exercise it says this: (Draw from one to the next in the order given,
and then draw from the last back to the first). When I connect the points in the given order I notice that I create two right triangles that meet at the right angles. So, the right alternative is D.

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#6 2021-02-25 20:48:31

Bob
Administrator
Registered: 2010-06-20
Posts: 10,053

Re: The Cartesian Coordinate System and the Distance Formula

hi jadewest

Your answers are the same as mine now.  Good! smile



Bob


Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob smile

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#7 2021-02-26 09:03:54

jadewest
Member
Registered: 2021-02-20
Posts: 44

Re: The Cartesian Coordinate System and the Distance Formula

Thank you for your help, I appreciate it!!

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