the worlds largest capital city and the country where it is located
That depends upon whether you're considering just the population within the city limits or the entire metro area. Many sources say the largest capital city is Tokyo, Japan.
However, you'll find the comparative populations within city limits here. This site names a Spanish-speaking capital as the largest.
http://www.infoplease.com/ipa/A0855603.html#axzz0yyaflVvy
It keep changing and depends upon whether you mean "largest" in population or area, and whether you count the entire metropolitan area. It also depends upon whether you consider Tokyo to be the capital of Japan. According to tradition and some written documents, Japan's capital is Kyoto. In actuality it is not.
The answer you are probably seeking, since this is a Spanish question, is Mexico City. Sao Paulo, Brazil was almost as large at last count.
Tokyo is larger than either of them.
The world's largest capital city by both land area and population is Tokyo. Tokyo is located in Japan.
To find the answer to this question, you could use various methods. One approach is to search on the internet using search engines such as Google. You can type in keywords such as "world's largest capital city" or "largest capital city by population and land area" to get relevant results.
Another method is to consult reliable reference sources such as books, encyclopedias, or atlases. These sources often provide comprehensive information about cities and countries worldwide.
It's always a good idea to cross-reference information from multiple sources to ensure accuracy and relevance.