how to find the determinant
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how to find the inverse of 2x2 matrix
what is the minor of an element
the determinant of the matrix obtained by deleting the row and column in which that element lies
when is a matrix singular and what does this mean?
when detM=0, so this matrix doesn't have an inverse
how to find the determinant
a(minor of a) -b(minor of b) +c(minor of c)
what is the transpose of a matrix?
changing the columns into rows, and vice versa
acronym and steps to inverse the 3x3 matrix A
Driving Monkeys Can’t Travel Fast
detA, matrix of minors, matrix of cofactors, transpose, apply the formula
how to form the matrix of cofactors
switch the sides' signs, keep the corners constant (and the middle)
the final formula in finding the inverse of a 3x3 matrix
how to form the 3x3 matrix in the simultaneous equations method
each row is the coefficients of x, y and z in each equation
how to solve matrix simultaneous equations
(matrix of coefficients)*(x,y,z matrix)=(matrix of answers to sim.eqs)
when do the planes meet at a single point
when the determinant is not 0
when do the planes form a sheaf
det=0, reduced to two equations which are consistent, the three equations aren’t multiples of each other
when are the planes the same plane
all three equations are multiples of each other
when do the planes form a prism
det=0, when reduced to two equations they are inconsistent, no rows of the matrix are multiples of each other
when are only two planes parallel
when only two rows of the matrix are multiples of each other
when are all the planes parallel
when all rows of the matrix are multiples of each other, but not the equations
what does the determinant of a transformation matrix represent
area scale factor
a rotation of A about the x axis
a rotation of θ about the y axis
a rotation of C about the z axis
det(AB)=
(detA)(detB)
(AB)⁻¹=
B⁻¹A⁻¹ (think of order of geometric transformations)