The normal form of the line x+y+1=0  is xcosα+ysinα=p then  α=

Reduce the equation x+y+1=0  in normal form.Separate the constant term and then divide both sides with  a2+b2=12+12=2  x2+y2=−12−x2−y2=12This can be rewrite as xcos5π4+ysin5π4=12  Compare this equation with  xcosα+ysinα=pHence,  α=5π4=3.93