Signs dependent on answers in 'Advice' section

[Josh Oldridge]

Hi,

Does anyone know if there is a way of making the signs between parts of an expression based on the next term? At the moment I have a + between each part of the answer (in red in the attached image), but this makes it look clunky when the answer is negative such as in the example, hence why I have brackets around. I tried putting a \simplify in front of the signs but couldn't work out how to get it working correctly. (The green terms are variable.)

Many thanks!

[Julia Goedecke]

Hello,

Have you tried putting simplify around the whole expression?

Julia

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[Christian Lawson-Perfect]

Hi Josh,

\simplify is the right thing to use. In order for it to work, you need to write the whole expression inside \simplify.

Your problems with \simplify might be partly down to the hats on the letters. You can't use LaTeX inside \simplify, so you need to use name annotations to get the hats.

If the coefficients of x, y and z are variables named a, b, c, respectively, this would produce the output you want:

$\simplify{ {a}*hat:x + {b}*hat:y + {c}*hat:z }$

I've made a question showing this at https://numbas.mathcentre.ac.uk/question/99006/put-hats-on-variable-names-inside-simplify/

I hope that helps!

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[Josh Oldridge]

Hi Julia. I have, but it said this made it an invalid expression, I think maybe because of the \hat for x, y, and z.

On Wed, 30 Jun 2021 at 10:29, Julia Goedecke <julia.g...@cantab.net> wrote:

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[Josh Oldridge]

Thanks so much for creating that example, Christian. I still can't quite get it to work in my case. It appears fine in the preview thing (below), but then doesn't work with what I have. Could it be because the dxdy, dydx, dzdy, etc. variables I have are expressions based on a diff function? Or maybe I'm doing something else wrong. I can grant access if you like?

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[Josh Oldridge]

Hi, it's working now! With normal () brackets around the {dzdy-dydz} etc it works.

Many thanks for your help.