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.
Answer:
45 square units
Step-by-step explanation:
You can cut the yellow figure into a triangle (4 by 5) and a rectangle (7 by 5).
Using the formula 
and 
area formulas, we get:
The area shaded in yellow is 45 square units
Answer:
The weight of 12 tennis balls = 691. 2 grams
Step-by-step explanation:
The weight of each tennis ball = 57.6 grams
So, the weight of 12 balls = 12 x ( weight of 1 ball)
= 12 x 57.6 grams
= 691.2 grams
⇒12 balls weigh 691.2 grams
Hence, the weight of 12 tennis balls = 691. 2 grams
Just think of it as normal subtraction. They both have the same denominators all you need to do is subtract. 11/12-7/12 is 4/12 if you simplify which just means to find the number that both 4 and 12 can go into equally the simplified answer would be 1/3. You just need to divide 4 by both the top and the bottom (numerator and denominator).
