Well as an Engineer I can say that Maths gets a lot nastier beyond where you stopped. I know I am never likely to use anything from my advanced numerical methods classes. If I find the need to wade hip deep in Jacobi polynomials again I will simply hire "friend mathematician" to do the work for me
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I don't see the lower levels of mathematics as a skill - it is more a training in rational thinking and reasoning. It sets people up with the confidence to approach any of life's problems in a logical and rational manner.