height of a triangle
h/b=sinA OR h=bsinA
area of an oblique triangle
law of cosines
heron’s area formula
standard formula for area of a triangle
1/2bh
component form of a vector
magnitude/length of a vector
vector addition formula
u + v = (u1 + v1, u2 + v2)
scalar multiple formula
ku = k(u1, u2) = (ku1, ku2)
dot product
u * v = u1v1 + u2v2
complex number z
z = a + bi
absolute value of a complex number (z)
distance between complex numbers (z1 & z2)
midpoint between complex numbers
trig form of complex number z
z = r(cosθ + isinθ) OR rcisθ
product of 2 complex numbers
r1r2[cos(θ1 + θ2) + isin (θ1 + θ2)]
quotient of 2 complex numbers
r1/r2[cos(θ1 - θ2) + isin(θ1 - θ2)]
demoivre’s theorem
nth powers of a complex number
(a + bi)^n
nth roots of a complex number
complex number from a trig form
when z = a +bi, r = √a² + b², θ = arctan(b/a)