Each angle is 90 degrees because 90 times 3 is 270.
Integral of 2sin(2x) is -cos(2x)
from 0 to pi/2 (sub pi/2 minus sub 0 for x) and then solve
= -cos(2*pi/2)-(-cos0)
= -cos pi + cos 0
= 1 + 1
= 2
<span>1. First, label the axis on your graph, with units:
time on the x-axis, in units of hours;
distance on the y-axis, in units of miles.
2. Draw a graph of distance vs. time. Distance after the first hour = 69 miles, distance after the 2nd hour = 138 miles, etc.
3. Observe that this graph is a STRAIGHT LINE with constant slope. Therefore the relationship is PROPORTIONAL.
For every other kind of graph -- i.e. not a straight line -- the relationship is NON-PROPORTIONAL.
Hope this helps. </span>
