## Calculus 10th Edition

$x + y = 1$
The slope is the vertical movement divided by the horizontal movement, from the coordinates of the intersections we can draw the conclusion that the vertical movement is $0 - a = -a$ and the horizontal movement is $a - 0 = a$ so the slope is $-a \div a = -1$. This means the equation for the required graph is $y = -x + a$, if we enter the coordinates (-3, 4) this gives us $4 = 3 + a$ $a = 1$ When you enter this in the equation from exercise 48 you get $x + y = 1$