Answer:
A + B + C = π ...... (1)
...........................................................................................................
L.H.S.
= ( cos A + cos B ) + cos C
= { 2 · cos[ ( A+B) / 2 ] · cos [ ( A-B) / 2 ] } + cos C
= { 2 · cos [ (π/2) - (C/2) ] · cos [ (A-B) / 2 ] } + cos C
= { 2 · sin( C/2 ) · cos [ (A-B) / 2 ] } + { 1 - 2 · sin² ( C/2 ) }
= 1 + 2 sin ( C/2 )· { cos [ (A -B) / 2 ] - sin ( C/2 ) }
= 1 + 2 sin ( C/2 )· { cos [ (A-B) / 2 ] - sin [ (π/2) - ( (A+B)/2 ) ] }
= 1 + 2 sin ( C/2 )· { cos [ (A-B) / 2 ] - cos [ (A+B)/ 2 ] }
= 1 + 2 sin ( C/2 )· 2 sin ( A/2 )· sin( B/2 ) ... ... ... (2)
= 1 + 4 sin(A/2) sin(B/2) sin(C/2)
= R.H.S. ............................. Q.E.D.
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In step (2), we used the Factorization formula
cos x - cos y = 2 sin [ (x+y)/2 ] · sin [ (y-x)/2 ]
Step-by-step explanation:
Answer: Second option, third option and fifth option.
Step-by-step explanation:
In order to solve this exercise it is important to remember the multiplication of signs:

Knowing that, you can distribute the sign and add the like terms. Repeat this procedure in each expression given in the exercise.
Therefore, you get:

You can identify that the expressions
,
and
are equivalent after simplifying.
Answer:
The number of deliveries that are predicted to be made to homes during a week with 50 deliveries to business is 87 deliveries
Step-by-step explanation:
The data categorization are;
The number of home deliveries = x
The number of delivery to businesses = y
The line of best fit is y = 0.555·x + 1.629
The number of deliveries that would be made to homes when 50 deliveries are made to businesses is found as follows;
We substitute y = 50 in the line of best fit to get;
50 = 0.555·x + 1.629 =
50 - 1.629 = 0.555·x
0.555·x = 48.371
x = 48.371/0.555= 87.155
Therefore, since we are dealing with deliveries, we approximate to the nearest whole number delivery which is 87 deliveries.
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