View Full Version : Precal test
horseridrgrl
Feb 4, 2007, 02:33 PM
How do I answer this question...
*** Write in standard form the equation of the parabola with the vertex (-2,3) that passes through (0,7).
sweetface125071
Mar 10, 2007, 04:35 PM
How do I answer this question....
*** Write in standard form the equation of the parabola with the vertex (-2,3) that passes through (0,7).
The vertex of the parabola would be (h,k)
the general eq of a parabola is (x-h)=4p(y-k) or (y-k)= 4p(x-h)
subsitute for h and k
the eq you use depends on when you graph the points if they are parallel to the y or x axis
Use the 2 points given and choose another point which would make the parabola symmetrical . With the three points you can write three eq and solve for p
asterisk_man
Mar 10, 2007, 08:30 PM
two points aren't enough to specify a parabola. In this case it could open either up or right. Also I'm not 100% sure of the previous poster's parabola equations. It's been a while but I thought there was an exponent in there somewhere.