A + B
= B + A
(A + B) + C
= A + (B + C)
k(A + B)
= kA + kB
AB (generally)
doesn’t = BA
(AB)C
= A(BC)
A(B + C)
= AB + AC
AA
= A^2
(A’)’
=A
(A + B)’
= A’ + B’
(kA)’
= kA’
(AB)’
=B’A’
AIor IA
=A
AA^-1
= I
4 Matrices to remember
Reflection in x axis, clockwise rotation, anti-clockwise rotation and dilation
Reflection in x axis matrix
(Cos2Ø Sin2Ø)
(Sin2Ø -Cos2Ø)
Anti clockwise rotation
(CosØ -SinØ)
(SinØ CosØ)
Clockwise Rotation
(CosØ SinØ)
(-SinØ CosØ)
Dilation for (ax,by)
(a 0)
(0 b)