Answer:
The Law of Cosine : cos C = 
Step-by-step explanation:
See the figure to understand the proof :
Let A Triangle ABC with sides a,b,c,
Draw a perpendicular on base AC of height H meet at point D
Divide base length b as AD = x -b and CD = x
By Pythagoras Theorem
In Triangle BDC And In Triangle BDA
a² = h² + x² ( 1 ) c² = h² + (x-b)²
c² = h² + x² + b² - 2xb ...(. 2)
From above eq 1 and 2
c² = (a² - x²) + x² + b² - 2xb
or, c² = a² + b² - 2xb .....(3)
Again in ΔBDC
cos C = 
Or, cos C = 
∴ x= a cos C
Now put ht value of x in eq 3
I.e, c² = a² + b² - 2ab cos C
Hence , cos C = Proved Answer
Answer:
I wish you luck
Step-by-step explanation:
X^2 + y^2 - 2x + 7y + 1 = 0
(x^2 - 2x) + (y^2 + 7y) + 1 = 0
(x^2 - 2x + 1) + (y^2 + 7y) + 1 = 0+1
(x^2 - 2x + 1) + (y^2 + 7y + 49/4) + 1 = 0+1+49/4
(x - 1)^2 + (y + 7/2)^2 + 1 = 0+1+49/4
(x - 1)^2 + (y + 7/2)^2 + 1-1 = 0+1+49/4-1
(x - 1)^2 + (y + 7/2)^2 = 49/4
(x - 1)^2 + (y + 7/2)^2 = (7/2)^2
The final answer is choice B
Answer:
C.) 3 1/6 hours
(won't let me write in fraction form, riip)
hopefully my answer helps! ♡
(if my answers helped you please tell me, therefore I know.. that I did them correctly or incorrectly. anyways, have a great day/night!)
Step-by-step explanation:
Multiply 6 1/3 by 1/2.
6 1/3 x 1/2 =
Answer:
3 1/6 hours
