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# C3 transformation of lnx graph help :)

1. Hey i have been doing some revision and forgot how this came about:

i was trying to draw the graph y=ln(3-x)

which i know that its a reflection in the y axis due to the -x but doesn't the positive 3 mean a translation in the x axis which means it moves left by 3/ but the example in the book says it moves right by 3?!

am i missing something here?

thanks for help xxx
2. (Original post by DreamsComeTrue.)
Hey i have been doing some revision and forgot how this came about:

i was trying to draw the graph y=ln(3-x)

which i know that its a reflection in the y axis due to the -x but doesn't the positive 3 mean a translation in the x axis which means it moves left by 3/ but the example in the book says it moves right by 3?!

am i missing something here?

thanks for help xxx
It should be reflected in the y-axis and moved 3 to the left.
3. (Original post by DreamsComeTrue.)
Am i missing something here?

thanks for help xxx
Yes, you are. The book is correct.

ln(3-x)

= ln (-(x-3))

So you are subtracting 3 from x and the graph is moved to the right.

See attached.

edit: You need to consider what has been done to the "x". The fact that there is a minus sign in front, is probably what confused the issue.
4. (Original post by ghostwalker)
Yes, you are. The book is correct.

ln(3-x)

= ln (-(x-3))

So you are subtracting 3 from x and the graph is moved to the right.

See attached.

edit: You need to consider what has been done to the "x". The fact that there is a minus sign in front, is probably what confused the issue.
your graph cuts the axis at wrong coordinates in your attached image
5. (Original post by rbnphlp)
your graph cuts the axis at wrong coordinates in your attached image
How so?

(Original post by rbnphlp)
when x=3 , y=0
Care to check that again.
6. When x is 0, y= ln 3 = 1.098...
When x = 2, y = 0
When x = 3 is undefined since as you go up to 3, the graph goes off to "minus infinity".
7. I believe you are Correct.

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