Verifying logarithm expressions with vectors in Matlab

[alexparker17]

Matlab Need urgent Help

Homework Statement

Create an appropriate vector 'x' and verify the equality of Right and Left hand sides of the expressions given above.

Homework Equations

Doing this by a/A=1 & b/B=1

The Attempt at a Solution

What i have done so far. But keep on getting this error at the bottom. Any help would be great


>> syms x
>> x=-10:1:10;
>> A=log(x+sqrt(x.^2.+1))

A =

Columns 1 through 13

-2.9982 -2.8934 -2.7765 -2.6441 -2.4918 -2.3124 -2.0947 -1.8184 -1.4436 -0.8814 0 0.8814 1.4436

Columns 14 through 21

1.8184 2.0947 2.3124 2.4918 2.6441 2.7765 2.8934 2.9982

>> B=log(x+sqrt(x.^2.-1))

B =

Columns 1 through 6

-2.9932 + 3.1416i -2.8873 + 3.1416i -2.7687 + 3.1416i -2.6339 + 3.1416i -2.4779 + 3.1416i -2.2924 + 3.1416i

Columns 7 through 12

-2.0634 + 3.1416i -1.7627 + 3.1416i -1.3170 + 3.1416i 0 + 3.1416i 0 + 1.5708i 0

Columns 13 through 18

1.3170 1.7627 2.0634 2.2924 2.4779 2.6339

Columns 19 through 21

2.7687 2.8873 2.9932

>> a;
? Undefined function or variable 'a'.

>> A;
>> a=(exp(x)-exp(-x))/2;
>> b=(exp(x)+exp(-x))/2;
>> inv(a)
? Error using ==> inv
Matrix must be square.

 

[Kavik]

What is the size of the "matrix" 'a'? What is one of the requirements for a matrix to have an inverse?

http://en.wikipedia.org/wiki/Invertible_matrix