The circumference of a circle is 34π

find the diameter and radius

put an explanation, i desperately need with finding diameter/radius with circumference

1- is the product of two rational numbers irrational or rational? first, make a hypothesis by multiplying two rational numbers. then, use variables such as x=a/b and y=c/d and the closure property of integers to prove your hypothesis. 2- what do you think the product of a nonzero rational number and an irrational number is? is it rational or irrational? make use of variables, the closure property of integers, and possibly a proof by contradiction to prove your hypothesis. 3- why do we have to specify that the rational number must be nonzero when we determine what the product of a nonzero rational number and an irrational number is? if the rational number were 0, would it give us the same result we found in part b?

Last one and the bottom answer choice is y=(x-4)^2+1 you guys!

Percent increase and decrease. original number: 45 new number: 18