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October 31, 2025, 03:39:21 am

Author Topic: Here's one for you  (Read 919 times)  Share 

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jasoN-

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Here's one for you
« on: September 15, 2010, 09:44:39 pm »
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Don't know how to do this help appreciated :)
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Martoman

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Re: Here's one for you
« Reply #1 on: September 15, 2010, 10:28:22 pm »
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Good Q.

The reason I choose to take tan of the angle i do is because the gradient makes that angle with the positive direction of the x axis.

Here's a solution... for...err...you.
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jasoN-

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Re: Here's one for you
« Reply #2 on: September 15, 2010, 10:36:12 pm »
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okay I get it, thanks a lot
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kakar0t

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Re: Here's one for you
« Reply #3 on: September 26, 2010, 08:50:22 pm »
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Hey Martoman, I understand the way you derived the magnitude for all the angles, but i don't get how you came to the conclusion that

m2 = tan(120+a)

Can you please elaborate why m2 equals that?

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brightsky

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Re: Here's one for you
« Reply #4 on: September 26, 2010, 09:09:40 pm »
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Draw a vertical straight line from the point of intersection to the x-axis. Look at the triangle made up of the line with gradient , the x-axis and the vertical line we just drew.

Let the magnitude of our vertical straight line be and the magnitude of the x-axis that is part of our triangle be . Then . But we don't know what is at the moment.

To find the value of it, apply the trig knowledge you learnt. We know that . We know one angle (barring the right angle) of our triangle, and that angle is as Martoman found. Apply this rule:



But we also know that

So
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kakar0t

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Re: Here's one for you
« Reply #5 on: September 28, 2010, 11:38:12 pm »
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Draw a vertical straight line from the point of intersection to the x-axis. Look at the triangle made up of the line with gradient , the x-axis and the vertical line we just drew.


I can't visualise this part :( Could you please elaborate on where the "vertical straight line" and the "point of intersection" are

This question = my downfall lol

brightsky

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Re: Here's one for you
« Reply #6 on: September 29, 2010, 02:02:24 pm »
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Draw a vertical straight line from the point of intersection to the x-axis. Look at the triangle made up of the line with gradient , the x-axis and the vertical line we just drew.


I can't visualise this part :( Could you please elaborate on where the "vertical straight line" and the "point of intersection" are

This question = my downfall lol

Oh woops, sorry, intersection is between the line with gradient and the line with gradient . Draw a vertical straight line from this point down to the x-axis. (I was drawing off Martoman's sketch btw).
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