Fundamental Theorem: integral(a,b) f(x)dx = F(b) - F(a) where F' = f
Basic Properties:
- integral(a,b) f = -integral(b,a) f
- integral(a,b) f = integral(a,c) f + integral(c,b) f
- integral(a,b) f(x)dx = integral(a,b) f(t)dt
- integral(a,b) [af + bg] = aintegral f + bintegral g
Symmetry Properties:
- King's Rule: integral(a,b) f(x) = integral(a,b) f(a+b-x)
- Even on [-a,a]: integral(-a,a) f = 2*integral(0,a) f
- Odd on [-a,a]: integral(-a,a) f = 0
- Queen's Rule: integral(0,2a) f = integral(0,a) [f(x)+f(2a-x)]
Periodicity:
- integral(0,nT) f = n*integral(0,T) f
- integral(a,a+T) f = integral(0,T) f
Leibniz Rule: d/dx integral(g(x),h(x)) f(t)dt = f(h(x))h'(x) - f(g(x))g'(x)
Riemann Sum: lim sum(r=0,n-1) f = integral(0,1) f(x)dx
Wallis' Formula: = integral(0,pi/2) x dx
- = []*I_(n-2)
- Even n: final factor pi/2. Odd n: final factor 1.
- =pi/2, =1, =pi/4, =2/3, =3pi/16
Standard Results:
- integral(0,pi/2) sin^ = pi/4
- integral(0,pi/2) ln(sinx) = integral(0,pi/2) ln(cosx) = -ln2
- integral(0,pi) x*f(sinx) = *integral(0,pi) f(sinx)
- integral(0,1) x^(m-1)(1-x)^(n-1) = (m-1)!(n-1)!/(m+n-1)!
Inequality: m <= f <= M on [a,b] => m(b-a) <= integral f <= M(b-a) Triangle Inequality: |integral f| <= integral |f|