So if 1/2 = 18 miles, we want to first find how many sets of 1/2 are in 21/2. We can just do this by dividing.
(21/2) / (1/2) = 21
So we know that there are 21 sets of 1/2 in 21/2, and since 1/2 and 18 are equal, we can say we know there are 21 sets of 18.
We can multiply to find this.
21 * 18 = 378
So two towns are 378 miles apart.
Cos(A-B) = cosAcosB + sinAsinB
<span>
cos(</span>π/2 - θ) = cos(π/2)cosθ + sin(π/2)sinθ
π/2 = 90°
cos(π/2) = cos90° = 0. sin(π/2) = sin90° = 1
cos(π/2 - θ) = cos(π/2)cosθ + sin(π/2)sin<span>θ
</span>
= 0*cosθ + 1*sin<span>θ = </span>sin<span>θ
Therefore </span>cos(π/2 - θ) = sin<span>θ
QED </span>
And what I need more information to answer your question.
x has two values 4 and 5 by factorization or using the general formula
