In technical writing, three terms/phrases not to be used:

• Intuitively, ...
• It is clear that ...
• It is obvious that ...

Just as well you could write

• Any idiot can plainly see ...

These phrases may be true for you, the writer. However, the reader won't have your depth of understanding of the subject matter and especially of the current notation and material. When the reader does not find the truth as plain as the unvarnished nose on your face, using these phrases directly affronts dear reader. As figure 17 plainly demonstrates both to the unaided eye and to any imbecile, obviously you shouldn't use these phrases. Even my pet gerbil knows using these phrases will insult anyone with a kindergarten education and clearly get your paper rejected posthaste.

Acknowledgments: I first heard this advice indirectly from Don Berry via a student taking a course from him. Berry gave extensive feedback on a writing assignment. The 'even my pet gerbil knows' phrase is courtesy of Andy Unger, MN chess expert.