I assume you're supposed to establish the identity,
cos(A) cos(2A) cos(4A) = 1/8 sin(8A) / sin(A)
Recall the double angle identity for sine:
sin(2<em>x</em>) = 2 sin(<em>x</em>) cos(<em>x</em>)
Then you have
sin(8A) = 2 sin(4A) cos(4A)
sin(8A) = 4 sin(2A) cos(2A) cos(4A)
sin(8A) = 8 sin(A) cos(A) cos(2A) cos(4A)
==> sin(8A)/(8 sin(A)) = cos(A) cos(2A) cos(4A)
as required.
2÷3 3 goes into 2 0 times so add 0 to make 20 3goes into 20 6 time so the answer is 0.6666666
The perimeter of the composite shape is: (3π + 12)mm
<h3>What is a semicircle?</h3>
A semicircle is a part of a circle cut through its diameter.
Analysis:
perimeter of a semicircle = πr
where r = 6/2 = 3mm
perimeter of a semicircle = π(3) = 3π
perimeter of incomplete rectangle = L+2B, L = 6mm, B = 3mm
perimeter of rectangle = 6mm +2 x 3= 12mm
perimeter of shape = (3π+12)mm
In conclusion, the perimeter of the rectangle is (3π+12)mm
Learn more about semicircles :brainly.com/question/285710
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The last one i think is correct, hope i could help??
