Question:
Solution:
I was working on question 10a trying to get the first required proof. However, I couldn't do it and checked the solution. The red arrow I have drawn on the solution shows what I have difficulty in understanding. Why can (k-u) become (k-x) when u=k-x? Thank you in advance and have a good day.
Solution:
I was working on question 10a trying to get the first required proof. However, I couldn't do it and checked the solution. The red arrow I have drawn on the solution shows what I have difficulty in understanding. Why can (k-u) become (k-x) when u=k-x? Thank you in advance and have a good day.