Finding roots of an exponential equation with multiple base numbers

Hey everyone, first post.

Just wondering if anyone can help me out with finding 'a' when the equation below is equal to 0


[IMG]file:///C:/Users/Jaiba/AppData/Local/Temp/moz-screenshot-2.jpg[/IMG][IMG]file:///C:/Users/Jaiba/AppData/Local/Temp/moz-screenshot-3.jpg[/IMG](94-10^a)*10^a*ln10+(118-16^a)*16^a*ln16+(147-25^a)*25^a*ln25+(180-40^a)*40^a*ln40+(230-60^a)*60^a*ln60



Cheers
[IMG]file:///C:/Users/Jaiba/AppData/Local/Temp/moz-screenshot.jpg[/IMG][IMG]file:///C:/Users/Jaiba/AppData/Local/Temp/moz-screenshot-1.jpg[/IMG]

Quote:

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Originally Posted by jvigar

Hey everyone, first post.

Just wondering if anyone can help me out with finding 'a' when the equation below is equal to 0


[IMG]file:///C:/Users/Jaiba/AppData/Local/Temp/moz-screenshot-2.jpg[/IMG]

[IMG]file:///C:/Users/Jaiba/AppData/Local/Temp/moz-screenshot-3.jpg[/IMG]

(94-10^a)*10^a*ln10+(118-16^a)*16^a*ln16+(147-25^a)*25^a*ln25+(180-40^a)*40^a*ln40+(230-60^a)*60^a*ln60



Cheers
[IMG]file:///C:/Users/Jaiba/AppData/Local/Temp/moz-screenshot.jpg[/IMG]

[IMG]file:///C:/Users/Jaiba/AppData/Local/Temp/moz-screenshot-1.jpg[/IMG]

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Welcome to the Forum (Party)

See if you want of copy an image from another site write like this

[img]image location [/img]

you can get the location of image by right clicking on the image and than -"copy image location"

sorry about that, I tried to paste directly from maple.

The equation is,

(94-10^a)*10^a*ln10+(118-16^a)*16^a*ln16+(147-25^a)*25^a*ln25+(180-40^a)*40^a*ln40+(230-60^a)*60^a*ln60 = 0

and I'm trying to find "a"

many thanks

Josh

Quote:

---

Originally Posted by jvigar

sorry about that, I tried to paste directly from maple.

The equation is,

(94-10^a)*10^a*ln10+(118-16^a)*16^a*ln16+(147-25^a)*25^a*ln25+(180-40^a)*40^a*ln40+(230-60^a)*60^a*ln60 = 0

and I'm trying to find "a"

many thanks

Josh

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Ask Maple for a numerical solution. It should give a ~= 1.3674 for the positive root (I have not checked for negative roots)

(you can't link to image files on your hard drive, they have to be on a machine that can been seen by the internet (such as an image hosting server), otherwise upload the image from the attachments dialog in the advanced editor)

CB

Thanks, I must have done something wrong in maple.

I ended up using newtons method in excel, and got the same value.

Thanks again for all your help

Josh