SOLUTION: Given point A(0,2) on the parabola y^2=x+4. Points B & C also lie on the curve such that BC is perpendicular to AB. Find the slopes and equation of the lines AB and BC. Give the ra

Algebra ->  Quadratic-relations-and-conic-sections -> SOLUTION: Given point A(0,2) on the parabola y^2=x+4. Points B & C also lie on the curve such that BC is perpendicular to AB. Find the slopes and equation of the lines AB and BC. Give the ra      Log On


   



Question 1040031: Given point A(0,2) on the parabola y^2=x+4. Points B & C also lie on the curve such that BC is perpendicular to AB. Find the slopes and equation of the lines AB and BC. Give the range of point C on the y-axis.
Thanks!

Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
Here is a plan for how to find the variable points B and C. I have not gone through the solution process to try this plan.

Sketch the parabola. It has points (0,2), (0,-2) and vertex (-4,0). Place a point B in the quadrant 1, and place point C in quadrant 2, with x-coordinate somewhat to the right of that of
B.

The parabola is of equation x=y%5E2-4.
Excuse the description of subscripted variable naming here, but point B would be y squared sub b minus 4, y sub b;
Point C would be y squared sub c minus 4, y sub c.
This would look good written on paper or in a conventional way.

You have A, B, C forming a right triangle allowing Pythagorean Theorem formula, and the slopes AB and BC, because they are perpendicular, are negative reciprocals of each other. This means you have a system of equations:



The parabola before any point labeling & drawing segments :graph%28300%2C300%2C-8%2C8%2C-8%2C8%2C-sqrt%28x%2B4%29%2Csqrt%28x%2B4%29%29