# Plotlegend does not work [closed]

I am trying to add a legend to a plot, but sometimes it work and sometimes it doesn't work and I don't understand why. For example, when I use the following code, I get as an error "Unknown option PlotLegend".

Plot[{Sin[x], Cos[x]}, {x, 0, 2 Pi}, PlotLegend -> {"sine", "cosine"}]

• The option's name is PlotLegends – Dr. belisarius Mar 24 '15 at 19:15

Plot[{Sin[x], Cos[x]}, {x, 0, 2 Pi}, PlotLegends -> {"sine", "cosine"}]

• flic.kr/p/rJJRTh You can see window of my Matematica with difference between PlotLegend and PlotLegends. And on the site, which you gave above, write about Needs["PlotLegends"] and there're red highlighted misspelling flic.kr/p/rM2Mwp – Roman Alexeev Mar 24 '15 at 17:56