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Dopamine1
Level 1
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Solved!

Can't solve exponential equation

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HP PRIME

Hello!
I can't figure out, what am I doing wrong? Why calculator doesn't find that x = 1/2 is the solution?
I tried to simplify the given answer, but it didn't help.
However, it solves another much simpler equation correctly, as you can see on the picture:
322123.png
Help me 😞

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Maké
Level 9
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Hi!, @Dopamine1:

 

Can you write, the equation ?.

 

I'm only see in the image, one light yellow triangle with gray border's.

Kind Regards !.
Have a nice day !.
@Maké (Technical Advisor Premium - HP Program Top Contributor).
Provost in HP Spanish Public Forum ... https://h30467.www3.hp.com/
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Dopamine1
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This is very strange. Here's how my post looks to me: https://pp.userapi.com/c638928/v638928620/31f54/JfM4Pxrc2Jg.jpg

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Maké
Level 9
3,551 3,490 180 541
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Hi!, @Dopamine1:

 

See, the images ...

 

IMG_20170511_131738.jpg

 

IMG_20170511_131703.jpg

 

Press, Num ... and Solve ...

IMG_20170511_131818.jpg

 

In comparison, with Wolfram Alpha ... http://www.wolframalpha.com/input/?i=solve(2%5E(8*x)*3%5E(4*x)%3D144)

IMG_20170511_131601.jpg

 

Kind Regards !.
Have a nice day !.
@Maké (Technical Advisor Premium - HP Program Top Contributor).
Provost in HP Spanish Public Forum ... https://h30467.www3.hp.com/
Jan_D
Level 6
305 297 32 76
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@Dopamine1 wrote:

Hello!
I can't figure out, what am I doing wrong? Why calculator doesn't find that x = 1/2 is the solution?
I tried to simplify the given answer, but it didn't help.
However, it solves another much simpler equation correctly, as you can see on the picture:


The Prime can solve your equation both exactly and numerically, so approximately.

 

Maké showed already that you can use the Solve app for solving numerically.

 

Another possibility is to use fsolve instead of solve, which will solve it numerically.

 

Also the Advanced Graphing app is very good in solving equations numerically.

We have 2 possibilities. We can plot the graph: 2^(8*X)*3^(4*X)=144, which is the equation for a simple straight line, or we can plot 2^(8*X)*3^(4*X)-144=Y and find its zeros.

 

We can get the zeros in Plot view by pressing Menu – Trace – PoI – X-Intercepts.

To get them more accuretely repeatedly press the + key.

 

The Prime can also solve the equation exactly but needs some help.

We have to rewrite 2^(8*x)*3^(4*x) by a linearisation and then solve the equation:

 

2017-05-13 16.33.37.jpg

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