I'm a software developer trying to grok Machine Learning. I have to understand trig (e.g. tanh and other sigmoid functions), calculus (e.g. derivatives, gradien

I'm a software developer trying to grok Machine Learning. I have to understand trig (e.g. tanh and other sigmoid functions), calculus (e.g. derivatives, gradients), linear algebra (e.g. vectors, matrices), probabilities, etc. Maybe it doesn't happen every day, but I need math.