I'm trying to refresh all of the mathematics I learned. I graduated with an engineering degree.

 

What are the best college level textbooks for calculus? Also, I'd like to get a better handle on trig, algebra, geometry, ie., all the easy stuff. I remember a lot of the easy stuff, but I'd like to learn all the proofs so I can have a full understanding of it all, so I can know it like the back of my hand.

 

My eventual goal is to go back to school to become a professional astronomer.

It probably won't be as good and as thorough as a real textbook, but it'll definitely give you a head start; try Khan Academy.

A good book that contains a little about a lot of the tools of theoretical physics is "Mathematical Physics" by Sadri Hassani. It maybe a little more advanced that you had in mind, but it does contain most of the mathematics you would need to make headway with astrophysics and gravitational physics. All the stuff an astronomer needs

 

Also it is written with physics in mind, so would most likely suit your background in engineering rather than pure mathematics.

 

Maybe more suited to your immediate needs in "Engineering Mathematics" by C.W. Evans.

If you have forgotten the basics, Wiley publish some "Teach yourself Calculus" etc books

If you want to learn Calculus from the ground up, proving virtually everything along the way I would suggest Calculus by Spivak. Although I will say it is not a book I would recommend if you want a refresher for applied calculus.

I have just bought the James Stewart Calculus book, 5th edition. I used the 4th edition my freshman year in college. I got rid of my edition a while ago, and decided using the book I was familiar with would be good. But I've heard conflicting reviews of Stewart's book, some very bad. What are your thoughts on this book, if you have any?

 

Thanks for the responses so far. Very helpful.

Unfortunately I've never used the textbook so can't give you any feedback. That being said if you have problems you can't understand then you're more than welcome to post them here for some assistance