The pairing of "basically literally" is very colloquial/informal and skews young. I hear it moderately frequently, mostly when people are recounting stories about personal interactions.
It means "I am emphatic that my description conveys an accurate feeling of a moment/interaction, but it isn't literally true--I am exaggerating or simplifying for story ...
I think you can pair a simplification with an exaggeration. Or, you can simplify a long, complicated story to a quick, one-line sentence, and that sentence can be an exaggeration. That seems to be the case here.
Definition of basically
1a : at a basic level : in fundamental disposition or nature
// basically correct
// basically, they are ...
There is a common and correct way of reading x = 3 sin(α)
x is equal to three sine alpha.
The use of "equal" as a verb to say "x equals..." is relatively modern. The word "equal" is still mostly used as an adjective except in mathematical contexts.
Given that a common colocation is "equal to", it is unsurprising that some people might treat the verb ...