but i do not agree with your opinion, i am using api, not designing api
I do not agree with your opinion. Even if you are just using the API, you will have to deal with matrix transformations at some point in your game and you will have to understand what are homogeneous coordinates to do it right.
Even if your API provides a complete math framework, you will have to know how to use it. To know how to use it you will have to learn maths and linear algebra.