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:
Area of cross section x height
Hope this helps
The smallest number of tiles Quintin will need in order to tile his floor is 20
The given parameters;
- number of different shapes of tiles available = 3
- area of each square shape tiles, A = 2000 cm²
- length of the floor, L = 10 m = 1000 cm
- width of the floor, W = 6 m = 600 cm
To find:
- the smallest number of tiles Quintin will need in order to tile his floor
Among the three different shapes available, total area of one is calculated as;

Area of the floor is calculated as;

The maximum number tiles needed (this will be possible if only one shape type is used)

When all the three different shape types are used we can get the smallest number of tiles needed.
The minimum or smallest number of tiles needed (this will be possible if all the 3 different shapes are used)

Thus, the smallest number of tiles Quintin will need in order to tile his floor is 20
Learn more here: brainly.com/question/13877427
I'm horrible at this so I'm just guessing.
X is the variable and x means multiplication symbol.
X + (X x 3 - 1) + (X x 3 - 1) - 4) <span>≥ 45 is the answer I got.
The answer to that inequality would be
X </span><span>≥ 7 I think.</span>
Answer:
60 as corresponding and alternate angles r equal
Step-by-step explanation: