Mehzorz

Hi! Im doing my homework questions, and one question asks me to: "Find a function r = f() which gives a spiral that always crosses the x-axis in a 45◦ angle" Now ive done several attempts to finding one, but i guess im confused on how it should cross, should it be hitting the axis every time at 45 degrees? If so, to precisely hit, would the spiral have to consist of straight lines? All help is appreciated Thank you!