Hi all, I am learning math and learning how to use the HP Prime as well.

How do I factorize 4x^2+36xy+81y^2 and get (2x+9y)^2 as a result?

Things I've tried in CAS view:

- factor(4x^2+36xy+81y^2) -> 36xy+4x^2+81y^2

- factors(4x^2+36xy+81y^2) -> [4*x^2+81*y^2+36*xy,1]

- simplify(4x^2+36xy+81y^2) -> 4x^2+36xy+81y^2

- collect(4x^2+36xy+81y^2) -> 4x^2+81y^2+36xy

- cfactor(4x^2+36xy+81y^2) -> 4x^2+81y^2+36xy

(08-23-2022 12:02 PM)rancom Wrote: [ -> ]Hi all, I am learning math and learning how to use the HP Prime as well.

How do I factorize 4x^2+36xy+81y^2 and get (2x+9y)^2 as a result?

Things I've tried in CAS view:

- factor(4x^2+36xy+81y^2) -> 36xy+4x^2+81y^2

- factors(4x^2+36xy+81y^2) -> [4*x^2+81*y^2+36*xy,1]

- simplify(4x^2+36xy+81y^2) -> 4x^2+36xy+81y^2

- collect(4x^2+36xy+81y^2) -> 4x^2+81y^2+36xy

- cfactor(4x^2+36xy+81y^2) -> 4x^2+81y^2+36xy

You have to put the multiplication sign between the numbers, the variable "x" and the variable "y".

Add a * between x and y, otherwise xy is interpreted as a single variable with a name identifier of length 2.

(08-23-2022 05:16 PM)robmio Wrote: [ -> ][quote='rancom' pid='163314' dateline='1661256139']

Hi all, I am learning math and learning how to use the HP Prime as well.

How do I factorize 4x^2+36xy+81y^2 and get (2x+9y)^2 as a result?

Things I've tried in CAS view:

- factor(4x^2+36xy+81y^2) -> 36xy+4x^2+81y^2

- factors(4x^2+36xy+81y^2) -> [4*x^2+81*y^2+36*xy,1]

- simplify(4x^2+36xy+81y^2) -> 4x^2+36xy+81y^2

- collect(4x^2+36xy+81y^2) -> 4x^2+81y^2+36xy

- cfactor(4x^2+36xy+81y^2) -> 4x^2+81y^2+36xy

You have to put the multiplication sign between the numbers, the variable "x" and the variable "y".

(08-23-2022 05:16 PM)robmio Wrote: [ -> ] (08-23-2022 12:02 PM)rancom Wrote: [ -> ]Hi all, I am learning math and learning how to use the HP Prime as well.

How do I factorize 4x^2+36xy+81y^2 and get (2x+9y)^2 as a result?

Things I've tried in CAS view:

- factor(4x^2+36xy+81y^2) -> 36xy+4x^2+81y^2

- factors(4x^2+36xy+81y^2) -> [4*x^2+81*y^2+36*xy,1]

- simplify(4x^2+36xy+81y^2) -> 4x^2+36xy+81y^2

- collect(4x^2+36xy+81y^2) -> 4x^2+81y^2+36xy

- cfactor(4x^2+36xy+81y^2) -> 4x^2+81y^2+36xy

You have to put the multiplication sign between the numbers, the variable "x" and the variable "y".

I don't believe you have to put a multiplication symbol between a number and its variable when entering the equation. For example entering; factor(4x^2+36x*y+81y^2) appears to be automatically interpreted as factor(4*x^2+36x*y+81*y^2) without having to enter the * after the 4, 36 or 81.

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(08-23-2022 05:30 PM)Steve Simpkin Wrote: [ -> ] (08-23-2022 05:16 PM)robmio Wrote: [ -> ]You have to put the multiplication sign between the numbers, the variable "x" and the variable "y".

I don't believe you have to put a multiplication symbol between a number and its variable when entering the equation. For example entering; factor(4x^2+36x*y+81y^2) appears to be automatically interpreted as factor(4*x^2+36x*y+81*y^2) without having to enter the * after the 4, 36 or 81.

Wow, I didn't know. Thank you so much for letting me know this possibility.

Regards, Roberto

It's beginning to look like Facebook here fellas, 1 or 2 of the same answers are probably enough... LOL

(08-23-2022 05:48 PM)rprosperi Wrote: [ -> ]It's beginning to look like Facebook here fellas, 1 or 2 of the same answers are probably enough... LOL

Oh, go put a multiplication sign in that!

I know that answers don't show up immediately for me so sometimes I answer a question that's been answered two or three times (or more!) before I see them.

(08-23-2022 05:48 PM)rprosperi Wrote: [ -> ]It's beginning to look like Facebook here fellas, 1 or 2 of the same answers are probably enough... LOL

I found out the answer guys, I have to add a multiplication sign between x and y.

In all seriousness, thank you all for this info!