# How do I rotate a parabola from opening up to opening horizontally?

##### 1 Answer

Aug 22, 2014

You can swap

Let's do an example for the inverse relation of

#x=y^2+6y+8#

#x=(y^2+6y)+8# start completing the square for#y#

#x=(y^2+6y+9)+8-9#

#x=(y+3)^2-1#

#x+1=(y+3)^2#

#+-sqrt(x+1)=y+3#

#-3+-sqrt(x+1)=y#

#y=-3+-sqrt(x+1)#

You will want to notice that the inverse is a relation and not a function because it doesn't pass the vertical line test.