(b) let g be a graph on vertices , vn, and let a be its adjacency matrix. show that g is connected if and only if every entry of the matrix i+a+a^2 + a^n-1 is non-zero, where i is the n x n identity matrix.

the correct option is 2.

step-by-step explanation:

according to the given information triangle abc is a right angle triangle with right angle at a. segment ab is 5 and segment ac is 7. point d is on segment bc and angles adb and adc are right angles.

it is given that triangles abd, cad, and cba are similar.

two triangles are similar if their corresponding sides are proportional.

in triangle cba, using pythagoras theorem

                      )

triangle abd and cba are similar,

                            (2)

triangle cad and cba are similar,

                      )

using (1), (2) and (3), we get

hence proved.

therefore option 2 is correct.

alright well the answers to your question is

2xy/9 hope this have a nice day : )

step-by-step explanation:

whatvare the choices

step-by-step explanation: