The houses form a right triangle. Using a²+b²=c² you will find that the distance from Clayton’s house to Danny’s would be 4.1 miles. Adding it all up, the distance would be 9.1 miles of walking.
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:
35/20
Step-by-step explanation:
20 divided by 4 = 5
so our multiple is 5
5 x 4 = 20
so we have to do the same to the numerator
5 x 7 = 35
Simplified= 1 3/5
The largest angle should be 66°
I hope this helps.
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