Consider points of the upper right branch of the hyperbola [math]x^2-y^2=16[/math] and on its asymptote [math]x=y[/math]. Find the [math]y[/math]-coordinates of the points on each for [math]x = 10, 100, 1000, 10,000[/math], and show that the vertical distance between corresponding points is decreasing as [math]x[/math] increases.
Consider a point [math](x_1,y_1)[/math] on the graph of [math]b^2x^2 - a^2y^2 = a^2b^2[/math].
- lab{3.4.12a} Find the slope of the tangent to the graph at [math](x_1,y_1)[/math].
- Write an equation of the tangent line in \ref{ex3.4.12a}.
- Show that [math]b^2xx_1-a^2yy_1=a^2b^2[/math] is an equation of the tangent line.
Consider a point [math](x_1,y_1)[/math] on the hyperbola [math]ax^2-by^2+cx+dy+e=0[/math] with [math]ab \gt 0[/math].
- lab{3.4.13a} Find the slope of the tangent to the graph at [math](x_1,y_1)[/math].
- Write an equation of the tangent line in \ref{ex3.4.13a}.
- Show that [math]axx_1-byy_1+\frac12c(x+x_1)+\frac12d(y+y_1)+e=0[/math] is an equation of the tangent line.
Show that the product of the distances of a point on the hyperbola [math]xy = -12[/math] to its asymptotes is a constant.
If the difference of the distances of the point [math](x,y)[/math] from two foci is zero, show that the locus of [math](x,y)[/math] is the perpendicular bisector of the line segment joining the foci.
Describe and sketch the graph of each of the following equations. If the graph is a circle, give its center and focus. If the graph is a parabola, give its focus, directrix, vertex, and axis. If the graph is an ellipse, give its center, foci, directrices, eccentricity, and length of major and minor axes. If the graph is an hyperbola, give its center, foci, directrices, eccentricity, asymptotes, vertices, and length of transverse axis.
- [math]x^2 + y^2 + 6x + 4y = 12[/math]
- [math]x^2 + 4y^2 + 6x + 4y + 6 = 0[/math]
- [math]x^2 + 6x + 4y + 2 = 0[/math]
- [math]x^2 - 4y^2 + 6x + 4y + 4 = 0[/math]
- [math]4y^2 + 6x + 4y + 13 = 0[/math]
- [math]xy + 6x + 4y = 3[/math]
- [math]3x^2 + 3y^2 + 6x - 18y = 162[/math]
- [math]4y^2 + x^2 + 6x + 4y = 11[/math]
- [math]y^2 = 9x^2 + 2y + 8[/math]
- [math]y^2 = 2y -9x^2 + 8[/math]