MATLAB: How to do the coding with plus minus sign infront of square root

plusminussquareroot

T = sqrt( 4 * I(2)^2 * I(3)^2 - E^2 );
first_result = -T / E;
second_result = +T / E;

If you prefer and if E is a scalar then

results = [-1 1] * sqrt( 4 * I(2)^2 * I(3)^2 - E^2 ) / E;

I am guessing about what the slash and subscript and superscript 2 and 3 are representing.

s=(-800/(2*.1))+[1 -1]*(sqrt(((800/(.1*2))^2)-(1/(.1*.000001))))

I don't think you can pad zero for a numeric number but you can do it when printing. For example

fprintf('num = %02d\n',2)

Is this what you want? HTH