Does "manifest" mean the same as show and illustrate?

Solution 1:

I wouldn't use manifest in your context. The dictionary definitions can be vague, but that's why most of them also give examples. So if you look at Cambridge, it says it means:

to show something clearly, through signs or actions

Which could make you think that the graph can "manifest" something. But when you look at the examples, you can intuitively understand that manifest really means to express OR show signs/symptoms of:

• The workers chose to manifest their dissatisfaction in a series of strikes. [express]
• Kipper manifested no joy or disappointment, but remained in his chair, calm and unconcerned. [showed signs of]

Here is another definition and example by OxfordL:

show (a quality or feeling) by one's acts or appearance; demonstrate.

• Lizzy manifested signs of severe depression [showed symptoms].

So manifest is rather used with abstract concepts like feelings, qualities, symptoms, signs. It would be uncommon to use it with a graph. This GNgram will show you which nouns are most commonly used as subjects of manifest. This other GNgram shows which nouns are most commonly the object of manifest.

I would stick to show and illustrate, and if you are too bored of them and wish to avoid repeating them all the time, there are always handy words like indicate, reveal, clarify, demonstrate, etc. depending on what you want to state in the sentence.