math – maravelias.info

Derivatives of non natural logarithms and exponentials

grigoris June 23, 2011 June 24, 2015

Some useful calculations to keep in mind !! > changing bases in logarithms: loga x = logb x / logb a for base 10 and e: log x = ln x / ln 10 (log e = 1 / ln 10) > derivative of exponential with other base: d (ax) …

Astronomy

Differential Equations -A

grigoris March 25, 2010 November 7, 2010

Solutions of a second order differential linear and homogeneous equation with constant coefficients: a y” + b y’ + c y = 0 (a ≠ 0) Solve the characteristic equation: a r2 + b r + c = 0 with general solutions r1,2=[(-b±√b2-4ac )/2a]. 1> if Δ=b2-4ac > 0 then …

Astronomy