problem on exponetials Please help please (1 Viewer)

Steven12

Lord Chubbington
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Mar 5, 2004
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sydney
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2004
question is
find the equation of the normal to the curve y=(x*2)(e*2x)
where * is (to the power of).at point where x=1

i tried this equation many times but keep getting the wrong answer
the correct answer on the sheet is suppose to be

x+4(e*2)y-4(e*4)-1=0

but i couldnt get that


is there anyone outthere who could help me on this one
please pleaase

Im crap at maths and i dont want to screw up my half yearlies cos it contribute to my final hsc mark................ arrrrrrrrrrrrrr:mad:
 

Heinz

The Musical Fruit
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Oct 6, 2003
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Canberra
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2004
y=x<sup>2</sup>e<sup>2x</sup>
y' = 2xe<sup>2x</sup> + 2x<sup>2</sup>e<sup>2x</sup>
@x=1, y = e<sup>2</sup>
@x = 1, y' = 2e<sup>2</sup> + 2e<sup>2</sup> = 4e<sup>2</sup>
:. normal = -1/ 4e<sup>2</sup>

y - e<sup>2</sup> = -1/ 4e<sup>2</sup>(x-1)
-4e<sup>2</sup>y + 4e<sup>4</sup> = x-1
x + 4e<sup>2</sup>y - 4e<sup>4</sup> - 1 = 0
 

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