Answer:
I can not answer for some reason
i am so so sorry i really was trying
Step-by-step explanation:
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 !
The equation has 0 real solutions.
If an equation has a negative discriminant, than there are no real solutions. We know this because the quadratic formula requires you to take the square root of the discriminant and therefore you would have all imaginary numbers.
The answer to the equation is 8
We know that,
Julia can finish a 20-mile bike ride in 1.2 hours.
The distance Julia travels is 20 miles and the time she takes is 1.2 hours.
So, Julia's speed =
= 16.67 mph
Katie can finish the same bike ride in 1.6 hours.
The distance Katie travels is 20 miles and the time she takes is 1.6 hours.
So, Katie's speed =
= 12.5 mph
Now, to find how much faster Julia rides than Katie we subtract Katie's speed from Julia's speed.
So, 16.67 mph - 12.5 mph = 4.17 mph = 4.2 mph (approximately)
Thus, Julia rides 4.2 mph faster than Katie.