The very best book for this isnt in C. The code examples are shown in an imaginary machine code. This allows you to take the algorithms general steps and convert them into any language you like. Its heavy going, expensive and absolutely worth its weight in gold. Its The art of computer programming by Donald Knuth. .
Alternatively their are several books based on C by authors such as robert sedgewick such as algorithms in C, problem solving in C. I found these books a mixed bag. Some people rave about sedgewicks books, I couldnt get past his babyish code errors.
I've been using the the math and physics section at GameDev.net primarily so far. I plan to write my own vector and matrix classes so I have a better understanding of the material once I feel I have enough knowledge of the math under my belt. I know my stuff will never be as good as what's out there already, but that's not my goal.
For B) the examples at gamedev.net seem awesome, at least for game development.
For C) again, the material at gamedev.net seems very nice for getting an idea of what can be done graphically using the math, etc. But you can learn how to use OpenGL and DirectX graphics libraries elsewhere, and I know OpenGL, and I'd be surprised if DirectX didn't, has the basic vector and matrix manipulations all set up for you so you don't have to do the actual math, just have an idea about what is happening (sort of like driving a car, if you're like me, you sort of have an idea about what's happening under hood, but not really). If you are trying to write a computer assisted drawing program or use the math for some purpose other than game programming, then the stuff at gamedev.net may or may not be much use to you except from a theoretical point of view, but I'd still take a look at the material available there.
Thank you very much for all who replied to my topic. I am doing image processing involves Gram-Schmidt Orthonormalization. As I am poor in maths, want to learn how to use maths concepts, in c programming.