Find an Equation of the tangent line to the parabola at the given point and find the x-intercept of the line...
I haven't learned derivatives yet. Can you solve it like this:
Find the y-intercept by equating the lenths of the two sides of the isosceles triangle formed by the tangent line and the y-axis. (d1 and d2).
I just don't know how to equate them...
and then for slope you would do the slope formula
equation of the parabola is
the tangent line and the parabola have equal y-values ...
since the tangent line touches the curve at a single point, the resulting quadratic has a single solution ... the discriminant must = 0
choose the positive slope
... now you have the slope of the tangent line and can finish whatever it is you need to do.