Question
How can I calculate the tangent lines at the intersection points of the y-axis?
x=4y-y^2
Answers
oobleck
the intersection points are (0,0) and (0,4)
dx/dy = 4-2y
so the slope is dy/dx = 1/(4-2y)
at (0,0) the slope is 1/4
at (0,4) the slope is -1/4
makes sense, since the graph is symmetric about the line y = 2
dx/dy = 4-2y
so the slope is dy/dx = 1/(4-2y)
at (0,0) the slope is 1/4
at (0,4) the slope is -1/4
makes sense, since the graph is symmetric about the line y = 2