described in subsequent sections. Quantity Unit Name Symbol watts [lumens] Radiant flux [Luminous flux] W [lm] Radiant energy [Quantity of light] joules [lumen sec.] J [lm·s] Irradiance [Illuminance] watts per square meter [lux] W/m [lx] Radiant emittance watts per square meter W/m [lm/m ] 2 [Luminous emittance
(19.206) 2 0 x 1 x 0 0 x2− x 0 0 1 Setting the derivative of f (2) to zero yields the coordinate x lm of the local minimum or maximum: x 1 x 0 1 x −2x 0 x lm = − · 2 2 m − 1 x − x f(x ) − f(x ) (19.207) with m = 1 0 · 2 1 x 2 x 1 f(x 1 − f(x ) 0 285 Appendix A Bibliography [1] A. Blum, Skriptum zur Vorlesung
