the hardest part of doing calculus is fluency in arithmetic, algebra and trigonometry. the most important idea in calculus is often glossed over, weakly presen

the hardest part of doing calculus is fluency in arithmetic, algebra and trigonometry. the most important idea in calculus is often glossed over, weakly presented or omitted entirely: the continuity of the reals. i feel that once this is fully understood, most of the ideas in calculus become intuitive.