Answer: ![\Large\boxed{C.~21}](https://tex.z-dn.net/?f=%5CLarge%5Cboxed%7BC.~21%7D)
Step-by-step explanation:
<u>The goal of the question</u>
Find the value of 2abcosC
<u>Given information</u>
a = 4
b = 3
c = 2
<u>Given formula (Law of Cosine)</u>
![c^2=a^2+b^2-2abcosC](https://tex.z-dn.net/?f=c%5E2%3Da%5E2%2Bb%5E2-2abcosC)
<u>Substitute values into the formula (Leave 2abcosC as it is)</u>
![(2)^2=(4)^2+(3)^2-2abcosC](https://tex.z-dn.net/?f=%282%29%5E2%3D%284%29%5E2%2B%283%29%5E2-2abcosC)
<u>Simplify the exponents</u>
![4=16+9-2abcosC](https://tex.z-dn.net/?f=4%3D16%2B9-2abcosC)
<u>Simplify by addition</u>
![4=25-2abcosC](https://tex.z-dn.net/?f=4%3D25-2abcosC)
<u>Add 2abcosC on both sides</u>
![4+2abcosC=25-2abcosC+2abcosC](https://tex.z-dn.net/?f=4%2B2abcosC%3D25-2abcosC%2B2abcosC)
![4+2abcosC=25](https://tex.z-dn.net/?f=4%2B2abcosC%3D25)
<u>Subtract 4 on both sides</u>
![4 + 2abcosC-4=25-4](https://tex.z-dn.net/?f=4%20%2B%202abcosC-4%3D25-4)
![\Large\boxed{2abcosC=21}](https://tex.z-dn.net/?f=%5CLarge%5Cboxed%7B2abcosC%3D21%7D)
Hope this helps!! :)
Please let me know if you have any questions
Answer:
0.5
Step-by-step explanation:
42 divided by 2/3 = 7
7 divided by 2/7 = 0.5
Answer:
26.69
Step-by-step explanation:
Answer:
The coordinates of the image of point A (2, -7) are A'(-1,-2).
Step-by-step explanation:
Note: The sign is missing between y and 5 in the rule of transitional.
Consider the rule of translation is
![(x,y)\Rightarrow (x-3,y+5)](https://tex.z-dn.net/?f=%28x%2Cy%29%5CRightarrow%20%28x-3%2Cy%2B5%29)
We need to find the image of point A (2, -7).
Substitute x=2 and y=-7 in the above rule.
![A(2,-7)\Rightarrow A'(2-3,-7+5)](https://tex.z-dn.net/?f=A%282%2C-7%29%5CRightarrow%20A%27%282-3%2C-7%2B5%29)
![A(2,-7)\Rightarrow A'(-1,-2)](https://tex.z-dn.net/?f=A%282%2C-7%29%5CRightarrow%20A%27%28-1%2C-2%29)
Therefore, the coordinates of the image of point A (2, -7) are A'(-1,-2).