What is the derivative of arctan (y/x) with respect to y? ?

Which of the following would represent the sum of 3 consecutive integers if x is the first integer?

Divide: 1573 ÷ 7 = a) 222 r5 b) 223 r6 c) 224 r5 d) 224 r3

Florence price's brownies and more sells all types of cookies and pastries. on tuesdays, they markdown all brownies 75% to a sale of $1.50 a dozen. find the selling price and the markdown of a dozen brownies.