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(1-10x)^4 does not expand
04-10-2019, 06:29 PM
Post: #1
(1-10x)^4 does not expand
Help, In HOME with HP Prime,

I enter (1-10x)^4 and expect something like #x^4+#x^3+#x^2+#x+c where # is any number.

However my result is (1.-10x)^4 which is just what I started with.

How do I get the binomial raised to the 4th power to expand?

Thanks - Cheers!
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04-10-2019, 06:45 PM
Post: #2
RE: (1-10x)^4 does not expand
Hi,
expand is an algebric CAS command, you can use it for polynomials and rational functions (powexpand for expressions with exponents and texpand for transcendent functions) Wink
Best,

Aries Smile
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04-10-2019, 06:59 PM
Post: #3
RE: (1-10x)^4 does not expand
Aries, Thank you for your reply.

I am still confused.

Are you saying that I cannot directly input (1-10x)^4 in the HOME textbox and get the expansion.

Are you saying I must use the powexpand command in the CAS textbox to get the expansion?

Cheers!
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04-10-2019, 07:13 PM
Post: #4
RE: (1-10x)^4 does not expand
Try CAS.expand('expression') or CAS.expand('expression','variable') in HOME mode Wink
Algebric objects need single quotes.
Best,

Aries Smile
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04-10-2019, 07:57 PM
Post: #5
RE: (1-10x)^4 does not expand
Either of these should work:

[HOME]
CAS("expand((1-10*x)^4)");
CAS.expand("(1-10*x)^4");

Note the multiplication sign at 10*x, to avoid implicit multiplication issues.
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04-10-2019, 08:26 PM
Post: #6
RE: (1-10x)^4 does not expand
Aries & DrD,

Thank you for replies. It is clear to me now. Cheers!
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04-11-2019, 06:21 AM
Post: #7
RE: (1-10x)^4 does not expand
Dont mention it !
Best,

Aries Smile
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