SEARCH HOME
Math CentralQuandaries & Queries

search

Question from Nazrul, a teacher:

If x is proportional to y and y is proportional to z , how can I prove that (x^2+y^2)^3/2 is proportional to z^3

Nazrul,

To say that p is proportional to q means that there is a constant so that p is the constant times q.

  • If x is proportional to y then there is a constant (I am going to call it C) so that x = Cy

  • If y is proportional to z there is a constant (this one I'll call K) so that y = Kz.

Use these two facts to eliminate x and y from the expression (x2+y2)3/2, and express it in terms of z. Is the result proportional to z3?

Harley

About Math Central
 

 


Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences.
Quandaries & Queries page Home page University of Regina PIMS