## Introduction

Hello friends,

New face to this community and Nice to be part of this community.This is my first post here. Hope everyone welcomes me. Thank you…

## Association and TemplateApply problem in associations section of The Wolfram Language:Fast introduction to programmers

I am going over The Wolfram Language:Fast introduction to programmers. In the associations section, following question and answer is given

Which of the following applies a template to make a string with appetizer and dessert from the association

`````` meal=<|"appetizer" →"nachos", "salad" → "spinach", "dessert" → "chocolate"|>
TemplateApply["The appetizer is `appetizer` and the dessert is `dessert`.", meal]
``````

But in my mathematica notebook, I am getting errors from the above two lines of code.

Incompatible elements in Join …. cannot be joined.

But according to web site, this is correct answer. Where is my mistake?

## Problem 8.8(a) Apostol introduction to analytic number theory

I am self studying analytic number theory from Tom Apostol and couldn’t solve this particular question which is 8(a) of chapter 8 on page 175.

It’s image:

Attempt: I thought of proving that for every $$a_i$$ that satisfies $$aequiv a_{i} (mod k_i)$$ will satisfy $$a_{i} equiv 1 (mod k_j)$$ .

But I couldn’t. Also, I realized that this will not prove existence of $$a_i$$ .

So, I am struck on this problem and need your help.

Thanks

## Introduction to new site

Hi guys,

This is my first post here. Nice to be part of this community. Hope everyone welcomes me.

## Which textbook provides the best introduction to Bitcoin?

REGARDING TEXTBOOKS ONLY:

The best one is `Bitcoin and Cryptocurrency Technologies` by Narayanan & Bonneau et al.
You can get a draft version for free from Arvind Narayanan’s blog.

The one by Andreas M. Antonopoulos, Mastering Bitcoin is good too.

Roger Wattenhofer & Christian Decker et al also wrote a nice one called “The Science of the Blockchain” about blockchains in general.

## My Introduction

• Big hello to admin and to all members of this forum. I am Alan, i from asia and We have a team working as freelancer on designing websites, software design and development.
We have created and worked on 100+ projects websites, plugins, templates and software. I joined this forum because I plan to share with you my knowledge and projects.
Looking forward to participate and interact with all you guys.
I wish all luck and success to everyone.

Figured it out, had to go to the old facebook style on my browser and was able to delete from there

## ux designer – Web/Mobile application introduction page practices

I have a web site, but the first time a user navigates there, I wish to do a small introduction of
the exact purpose of the web site, ie. explain what we can do with it and how etc…

I have seen such on Pinterest by example, the first time you navigate the gives a short introduction like this:

So, I have a few questions:

• Is it good practices ? or not ?
• Are there other approaches?
• Does having animation is interesting ? do we need them or not and why?
• Is it better to use “real photo” or “drawing”… I have the feeling that photos are more concrete.
• Does this kind of specific page have a specific name? It is not a landing page, right?
• Are there other examples and/or alternatives.
• How can we have such kind of introduction on mobile?
• Should I directly propose a registration or propose to continue on the web site?
What is the best for engagement & retention?