What is the difference between 原因 and 要因, 解析 and 分析?

Question

When I search meaning, both 原因 and 要因 mean cause.

解析 and 分析 mean analysis.

But I think there will be little different meaning.

Answer 1

From my personal experience,

「原因」 is like a general cause, perhaps one of many.

「原因は結果の反対語である」 - "The cause is the opposite of the result"

「要因」 is the primary cause.

「他の原因はたくさんあったのですが、飲酒運転が要因だったようです。」 
  - "Though there were many other factors, drunk driving seems to have been the primary cause"

「解析」 is a word for the process of developing a logical theory about how something works or how or why something happened by analyzing the information already available, like when you analyze statistics.

「経済を解析するプロジェクト」 - "a project to analyze the economy"

「分析」 is a general word for breaking something up and analyzing its parts to get more information about it, like you might analyze a meteorite.

「事故の原因はまだ分析しなければなりません」 
  - "(We) still need to analyze the causes of the accident"