Hi, I'm in first year engineering and I have trouble understanding where this formula comes from in determining the relationship between the coefficient of volume expansion and the coeff of linear expansion. dV=(dV/dL)*dL = 3L^2*dL now i know that they changed the dV in the brackets to dL^3, but then I don't understand how dL^3/dL became 3L^2? Is there a part of calculus I am missing? does it have to do with a rate of change divided by a rate of change? Thanks!