Study Guide B l o c k 4: Matrix A l g e b r a U n i t 2: 1. I n t r o d u c t i o n t o Matrix A l g e b r a L e c t u r e 4.020 Study Guide Block 4: M a t r i x Algebra U n i t 2 : I n t r o d u c t i o n t o M a t r i x Alqebra Lecture 4.020 continued Study Guide Block 4 : M a t r i x Algebra U n i t 2 : I n t r o d u c t i o n t o M a t r i x Algebra 2. Read: Supplementary N o t e s , Chapter 6', S e c t i o n D 3. ( O p t i o n a l ) Read: Thomas, S e c t i o n 13.2 Exercises Show t h a t A ( B + C) = AB + AC and A ( B C ) = ( A B ) C where A , B , and C a r e each 2 x 2 matrices. ) 1 1 Let A = i0. 0 and 0 = 0 o) a. F i n d a l l m a t r i c e s B s u c h t h a t AB = 0 . b. Find a l l m a t r i c e s C s u c h t h a t AC = 0 b u t CA f 0. Let A = (: -:) a nd 0 =(: i). Find a l l m a t r i c e s B s u c h t h a t AB = 0 Let A = (: -:), =(: :) B and I =(' 0 a. F i n d a m a t r i x X s u c h t h a t AX = I b. Does t h e r e e x i s t a m a t r i x X s u c h t h a t BX = IZ For any s q u a r e m a t r i x A, we d e f i n e r i s any p o s i t i v e i n t e g e r , a. Compute if A = b. Compute if A = c3 - t o mean AA.. .A, where n times i: 1) ( c o n t i n u e d on t h e n e x t page) 4.2.3 Study Guide Block 4: M a t r i x Algebra U n i t 2: I n t r o d u c t i o n t o M a t r i x Algebra - 4.2.5 (continued) . Compute A Let A and ' A =(: ) if A and l e t I = 1 (i -- :) Compute - b. Compute u s i n g t h e r e s u l t of p a r t ( a ) . c. Compute A - - 3 a. 2A -- =(-: -:-:) 1 c. - 24 I 7 4.2.7 Let A = ( ) . Find a l l m a t r i c e s I3 s u c h t h a t AB = BA. 4.2.8 I f A i s any m a t r i x , w e d e f i n e t h e t r a n s p o s e of A, w r i t t e n A T t o b e t h e matrix o b t a i n e d when we i n t e r c h a n g e t h e rows and columns of A. T h a t is, t h e columns of A a r e t h e rows of A 2 What is if A = T T I f A i s any m a t r i x , compute (A ) . I f A and B a r e 2 x 2 m a t r i c e s show t h a t T Find a l l 2 x 2 matrices A f o r which AAT = A A. T . , MIT OpenCourseWare http://ocw.mit.edu Resource: Calculus Revisited: Multivariable Calculus Prof. Herbert Gross The following may not correspond to a particular course on MIT OpenCourseWare, but has been provided by the author as an individual learning resource. For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms.