Answer:

Step-by-step explanation:

The exact value of cos120 if the measure 120 degrees intersects the unit circle at point (-1/2,√3/2) is 0.5
<h3>Solving trigonometry identity</h3>
If an angle of measure 120 degrees intersects the unit circle at point (-1/2,√3/2), the measure of cos(120) can be expressed as;
Cos120 = cos(90 + 30)
Using the cosine rule of addition
cos(90 + 30) = cos90cos30 - sin90sin30
cos(90 + 30) = 0(√3/2) - 1(0.5)
cos(90 + 30) = 0 - 0.5
cos(90 + 30) = 0.5
Hence the exact value of cos120 if the measure 120 degrees intersects the unit circle at point (-1/2,√3/2) is 0.5
Learn more on unit circle here: brainly.com/question/23989157
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Answer:
-28
Step-by-step explanation:
-4(7)=-28
Answer:
A) 14
Step-by-step explanation:
BC is congruent to DC in saying this you can plug the equations to each other and solve for y and then put its back into the equation for BC to get the length.
3y+5=5y-1
subtract 3y from both sides --> 5=2y-1
add 1 to both sides --> 6=2y
now get y alone, divide by 2 by both side --> y=3
plug y in back to 5y-1 --> 5x3-1
15-1
BC = 14