Recall the sum identity for cosine:
cos(a + b) = cos(a) cos(b) - sin(a) sin(b)
so that
cos(a + b) = 12/13 cos(a) - 8/17 sin(b)
Since both a and b terminate in the first quadrant, we know that both cos(a) and sin(b) are positive. Then using the Pythagorean identity,
cos²(a) + sin²(a) = 1 ⇒ cos(a) = √(1 - sin²(a)) = 15/17
cos²(b) + sin²(b) = 1 ⇒ sin(b) = √(1 - cos²(b)) = 5/13
Then
cos(a + b) = 12/13 • 15/17 - 8/17 • 5/13 = 140/221
Answer:
Your table is filled in below.
Step-by-step explanation:
The scale factor is the ratio of image size to original size. In part (d), the image height is "blocks" while the original height is "feet". So, the units of the scale factor are "blocks/ft".
Sometimes a scale factor has units, like this, and sometimes it is expressed as a pure number. A map scale factor might be the pure number ratio 1 : 62500, or it could also be expressed with units as 1 in : 1 mile.*
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* actually, these are slightly different scales. 1:62500 is about 0.98643 inches per mile.
Answer:
6 stuffed animals
Step-by-step explanation:
if 1/4= 1 then 1x6= 1 1/2
The key calculation in this problem is figuring out <em>how many times 80 goes into 1,000,000</em>. I'll build up in steps here.
80 x 5 = 400. This gives us a building block on our way to 1,000,000. From here, we can go further and say that 400 x 5 = 2,000; that 2,000 x 5 = 10,000; and finally that 10,000 x 100 = 1,000,000. Altogether, starting from 80, that's
80 x 5 x 5 x 5 x 100 = 80 x 25 x 500 = <em>80 x 12,500</em>
So, since 80 goes into one million 12,500 times, it takes 12,500 minutes for the animal's heart to beat that 1,000,000 times.
He can make 5 sculptures.
We divide the amount of clay, 14 pounds, by the amount it takes to make one sculpture, 2 4/5 pounds:
14 ÷ 2/45 = 14 ÷ 14/5 = 14/1 ÷14/5 = 14/1 × 5/14 = 70/14 = 5
