<span>1. Find a ⋅ b.
a = <7, 4>, b = <3, 5> (2 points)
41 <---------- right answer
<10, 9>
-1
<21, 20>
Explanation:
a . b means the dot or scalar product of the vectors a and b.
The scalar product of vectorr <x1,y2> and <x2,y2> is (x1)*(y1) + (x2)*(y2)
So, a . b = 7*3 + 4*5 = 21 + 20 = 41 <-------- answer
2. Find a ⋅ b
a = 10i + 9j, b = 4i + 3j (2 points)
<40, 27>
<14, 12> 67 <---------- answer
-13
Explanation: Again you are required to find the dot product of two vectors. In this case the vectors are given using the representation with the unit vectors i and j.
The dot product of the vectors (x1 i + y1 j) . (x2 i + y2 j) is x1*x2 + y1*y2
Time since the storm started is always positive. The values of x are positive in quadrants 1 and 4.
Temperatures in a blizzard are not always terribly cold. Some of the coldest snowstorms on record have temperatures in the range of +5 °F to +18 °F. These values are negative temperatures on the Celsius scale, so the quadrant used for plotting them will depend on the temperature scale you choose.
While temperatures in Alaska can be well below zero (on either the F or C temperature scales), the air usually has to warm up to the range indicated above before it can snow. US temperatures are generally reported using the Fahrenheit scale, but weather records are often kept using the Celsius scale.
I would be inclined to choose "Quadrant 1 and 4 only", but arguments can be made for "1 only" and "4 only" as suggested above.