C5 W2 problem in quiz

Here is one question from my quiz for course 2. I don’t think any other answer will be correct other than mine as Theta_t and ec both have different dimensions. Theta_t is (10000 x 1) while ec is (100 x 1). Please correct me if I’m wrong.

Consider this, if \theta_t is a (10000 x 1) dimensional matrix, and if e_C is a (100 x 1) dimensional matrix, how are you supposed to carry out the matrix multiplication \theta_t^Te_C?

Also, if the multiplication \theta_t^Te_C does’t resolve into a scalar, then how will you take the exponential? Even if you think of it as taking the exponential element-wise, then both the numerator and the denominator will be a matrix, how will you do the division of 2 matrices?

Please do watch the lecture video once again, and do let us know if that helps.


ig I confused O and theta_t with each other!
Thanks for the help !!