PURE Flashcards
i^2 = ?
-1
i^3 = ?
-i
i^4 = ?
1
cos(-a) = ?
cos(a)
sin(-a) = ?
-sin(a)
tan(-a) = ?
-tan(a)
What is modulus argument form?
z = r(cos(a)+isin(a))
How do you invert a 3x3 matrix?
-Find the determinant
-Replace every element in the matrix by its minor
-Switch the sign of alternate elements
-Transpose the matrix
-Divide by the determinant
If the coeffiecient matrix for a set of linear equations is singular then…
Either
-the equations have no solutions
Or
-the equations have an infinte number of solutions
If the coeffiecient matrix for a set of linear equations is non-singular then…
The equations have a unique solution
If there is a unique solution…
The three planes intersect at a single point
If there are infinitely many solutions…
Either
-The three planes intersect on a common line (sheaf)
Or
-The planes are the same
If there are no solutions…
Either
-The planes are parallel
Or
-The planes intersect to form a triangular prism
What are the 4 types of linear transformation?
REFLECTION in the line…
ROTATION about the origin by … anti/clockwise
STRETCH parallel to the x/y axis by scale factor…
ENLARGEMENT with centre (0.0), by scale factor…
What does the inverse of a linear transformation do?
Reverses original transformation
What does the modulus of the determinant of the transformation matrix represent?
The area scale factor of the transformation
What is an invariant point?
A point that has been transformed onto itself
If the determinant of the transformation is negative, what does this tell you?
A reflection has taken place
What is a line of invariant points?
A line on which every point on that line is invariant
The point (x,y) is invariant if…
M(x y) = (x y)
Use this to find invariant lines