## SamIam 4 years ago Help please :D

1. SAMIAM

2. SAMIAM

I need help with part c

3. razor99

srry

4. SAMIAM

mth3v4 Can you help me plz????

5. anonymous

im not very good with marices but ill "try"

6. SAMIAM

okkiedokieee

7. anonymous

it will probably take time pulling books

8. SAMIAM

lol Thanx

9. razor99

did u told me that question

10. SAMIAM

sorry?

11. anonymous

sorries :(

12. anonymous

dont know this 1

13. razor99

r u ok mth3v4

14. anonymous

I apologize, I didn't know you wanted me to help with this question. I'm taking a look now.

15. SAMIAM

thanks jemurray. I was busy fighting with someone on os

16. SAMIAM

So it was fine lol

17. anonymous

Okay, these are just asking for relatively simple verifications. Let me show you how to do the first one.

18. razor99

Jemurray3 and SamIam are typing replies…

19. SAMIAM

ok i did the first two parts but let me see what u got i really need part c

20. SAMIAM

Razor are you ok?

21. anonymous

Oh, okay, well if you did the first two I won't bother :) Watch now: $A^{-1}\cdot A = \frac{1}{5}(2I - A) \cdot A = \frac{1}{5}(2I\cdot A - A^2)$ but since $A^2 -2IA + 5I = 0$ as per the assumption, then $2IA - A^2 = 5I$ so plugging that in yields $\frac{1}{5}(5I) = I$ So that is in fact the proper inverse matrix.

22. SAMIAM

Just processing it give me a sec :D

23. SAMIAM

OHHHH GOTTTT ITTTTT Thankx jemurray :D

24. anonymous

No problem :)

25. SAMIAM

R u gonna be around fro much longer?

26. anonymous

For a little while

27. SAMIAM

ok i may be back :D