13=3x-x/2
13=5x/2
26=5x
X=5.2
Answer:
Step-by-step explanation:
we know that
The Pythagorean Theorem states that in a right triangle
where
c is the greater side (the hypotenuse)
a and b are the legs
In this problem
Let
c=AB ---> distance from point A to point B
a ---> the difference of the x-coordinates both points
b ---> the difference of the y-coordinates both points
so
substitute
Answer:
b
Step-by-step explanation:
b is the right answer
it is
sure
it equals <span>(−<span>12</span>)</span> because <span><span>cos<span>(<span>60∘</span>)</span></span>=<span>12</span></span>
Explanation:
The reference angle for <span>240∘</span> is <span>60∘</span> (since <span><span>240∘</span>=<span>180∘</span>+<span>60∘</span></span>)
<span>60∘</span> is an angle of one of the standard triangles with
<span><span>cos<span>(<span>60∘</span>)</span></span>=<span>12</span></span>
<span>240∘</span> is in the 3rd quadrant so (either by CAST or noting that the "x-side" of the associate triangle is negative)
<span><span>cos<span>(<span>240∘</span>)</span></span>=−<span>cos<span>(<span>60∘</span>)</span></span></span>
<span><span>cos<span>(<span>240∘</span>)</span></span>=−<span><span>12</span></span></span>
