Hope you can help. Is the grammar/spelling in this sentence right?

I have an extensive understanding of the underlying principles of the analysises due to my strong mathematical background having studied the “Mathematical Line” at “Gymnasium”, upper-secondary school in Germany.
This may be a little more fluent, and to the point:

Having extensively studied the “Mathematical Line” at Gymnasium, upper-secondary school in Germany, I fully understand the underlying principles of analytical thinking.

Dear Anonymous,

«Gymnasium» is «grammar school» in English. I do not know what «the mathematics line» is in English. I do not think there is a division between the mathematical subjects and the linguistic subjects in English schools, unless it is perhaps «arts and sciences.»

Kind regards, Emotion: smile