I have been re-visiting old topics recently in prep. for the c2 exam. Today I am doing circles, but I can't do this question. I know I have done it before, but I have forgotten which makes it even more frustrating
Show that the circle with equation x² + y² - 2ax - 2bx + b² = 0 touches the Y-axis.
I don't think you can answer this question unless you have the values for a and b as they're the numbers that give you the translation from your original circle..
I think that you have copied the question incorrectly and you should have -2by not -2bx
I double checked and the way I copied it is the way its in the book, but maybe this is a typo in the book? Out of interest, what would you do if it was -2by?