How can I calculate the focus of a parabola?

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Answer 1 · 2017-04-15T20:26:55

#"please have a look the fallowing details."#

#"if you have an equation in the vertex form "f=a(x-h)^2+k ,"#
#"focus is " (h,k+1/(4a))#

#"example :"#

#y=2(x-1)+1#

#a=2" , "h=1" , "k=1#

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#"Focus "A=(h,k+1/(4a))#

#A=(1,1+1/(4*2))#

#A=(1,1+1/8)#

#A=(1,9/8)#