As soon as I read this, the words "law of cosines" popped
into my head. I don't have a good intuitive feeling for the
law of cosines, but I went and looked it up (you probably
could have done that), and I found that it's exactly what
you need for this problem.
The "law of cosines" relates the lengths of the sides of any
triangle to the cosine of one of its angles ... just what we need,
since we know all the sides, and we want to find one of the angles.
To find angle-B, the law of cosines says
b² = a² + c² - 2 a c cosine(B)
B = angle-B
b = the side opposite angle-B = 1.4
a, c = the other 2 sides = 1 and 1.9
(1.4)² = (1)² + (1.9)² - (2 x 1 x 1.9) cos(B)
1.96 = (1) + (3.61) - (3.8) cos(B)
Add 3.8 cos(B) from each side:
1.96 + 3.8 cos(B) = 4.61
Subtract 1.96 from each side:
3.8 cos(B) = 2.65
Divide each side by 3.8 :
cos(B) = 0.69737 (rounded)
Whipping out the
trusty calculator:
B = the angle whose cosine is 0.69737
= 45.784° .
Now, for the first time, I'll take a deep breath, then hold it
while I look back at the question and see whether this is
anywhere near one of the choices ...
By gosh ! Choice 'B' is 45.8° ! yay !
I'll bet that's it !
Answer: 18mph
Step-by-step explanation:
Given data
total distance driven = 396 miles
time driven = 8 am Tuesday to 5 pm Wednesday
total time driven in hours = 33 hours
lunch break time = 30 min Tuesday + 30 min Wednesday
= 60 min
= 1 hour
sleep time = 7 pm Tuesday to 5 am Wednesday
= 10 hours
solution:
To find the average speed,
we are given total time driven = 33hrs.
lunch + rest time = 10hrs + 1hr
= 11hrs
total time travelled =drive time - rest + lunch time
= 33 - 11
= 22hrs
therefore;
average speed = distance / time traveled.
average speed = 396 / 22
average speed = 18 mph
Answer:
y= 5x-3
Step-by-step explanation:
We have an intercept of -3 and a slope of 5
We can use the slope intercept form of the equation
y= mx+b where m is the slope and b is the y intercept
Substituting in the known values.
y= 5x-3
Answer:
m= 1/2
Step-by-step explanation:
