91Ó°ÊÓ

The lines $y=2x-1$and $y=ax+2$are perpendicular if$a=$____.

True or False :

The y-coordinate of a point at which the

graph crosses or touches the x-axis is an x-intercept.

Open the origin symmetry applet. Move point A around the Cartesian plane with your mouse. How are the coordinates of point A and the coordinates of point B related?

In Problems 89–96, graph each equation using a graphing utility. Use a graphing utility to approximate the intercepts rounded to two decimal places. Use the TABLE feature to help to establish the viewing window.

$y=-3x+14$

Find the slope and y-intercept of each line. Graph the line by hand. Verify using a graphing utility.

$3x+2y=0$

In Problems 89–96, graph each equation using a graphing utility. Use a graphing utility to approximate the intercepts rounded to two decimal places. Use the TABLE feature to help to establish the viewing window.

$y=2x^2-15$

(a) Find the intercepts of the graph of the equation

(b) Graph the equation

$2x+3y=6$

(a) Find the intercepts of the graph of the equation

(b) Graph the equation

$3x-2y=6$

In Problems 89–96, graph each equation using a graphing utility. Use a graphing utility to approximate the intercepts rounded to two decimal places. Use the TABLE feature to help to establish the viewing window.

$y=-3x^2+19$

(a) Find the intercepts of the graph of the equation

(b) Graph the equation

$-4x+5y=40$