how to solve equations using graphs???plzzz help

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awsome12345

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i knw how to solve the tangents and gradient,i am askin bout the others,,,for e.g Q:solve the equation x^2-2x/4x^2+3+4x=0 ???????
 
Aahmsil

Aahmsil

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Which paper ?

Do you have the question number and year or is it possible for you to post a link because that would make it easier to help :Search:
 
Aahmsil

Aahmsil

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Ah, forget it !!!

Part (a) (i)
I guess you're capable enough to calculate and get the answers as 1.5, 3.75 and -1.5

Part (a) (ii)
Drawing the graph..............................................................................

Part (b)
Here since y = x/2 - 2/x, all you have to do is find the two x values when the y value is one.
In the question: x/2 - 2/x = 1
Answers: (Approximately)
1) -1.2
2) 3.2

Part (c) (i)
This part should be easy as well.
Answer will be around 0.967

Part (c) (ii)
The answer will be the same to Part (c) (i) because both points lie on the same line; y = 0

Part (d) (i)
The line y = -x will have to be drawn plotting appropriate points.

Part (d) (ii)
This is a peculiar question but if you're watchful enough you can easily solve it !!!

Recall that the first graph we drew had an equation of y = x/2 - 2/x

Then in Part (d) (i) we drew another graph, this time with the equation y = -x

See a similarity ?

The question states; Use your graphs to solve the equation x/2 - 2/x = -x

In other words, this equation literally asks for the value at which these two graphs are equal, which is nothing but their points of intersection !!!

Which values should we enter then; x or y ???
Look at the answer space and you should see that it says 'Answer (d) (ii) x = ......... or x = .........' which provides you with one valuable clue that they're looking for the x values of the intersections of the two graphs !!!

So find the two points, the answers should approximately be around:
1) -1.15
2) 1.15

Hope that helped !!! :)

Cheers !!! :good:
 
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