Ab←→ is perpendicular to cd←→. how many 90° angles are formed by the intersection?

4

Step-by-step explanation:

If two lines are perpendicular to each other, they are said to create a 90° angle at the point of intersection.

There are clearly four 90° angles when lines AB and CD meet at 90°. It is shown in the picture attached. [Note: even if you translate the intersection point up or down, still there are four 90° angles.]

f(x) has value 150 at x= 0

and 0 at x= 3

so d(f(x))/dt = slope = -150/3 = -50