Answer:this look really hard to answer i tried everyth
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Step-by-step explanation:
They're used to measure or divide things¿
Answer:
BC
Step-by-step explanation:
The longest side has the greatest angle opposite to it, 85 deg is the greatest angle, BC is the longest side
Since cosine is negative in the second and 3rd quadrant, the required angles are 120 and 240 degrees
<h3>Trigonometry identity</h3>
Trigonometry identities are expressed as a function of cosine, sine and tangent.
Given the trigonometry expression shown
4cos2θ+9=−14cosθ
Equate to zero
4cos2θ+9 + 14cosθ = 0
According to trig identity
cos2θ = 2cos²θ - 1
Substitute to have:
4(2cos²θ - 1)+9 + 14cosθ = 0
Expand
8cos²θ - 4 + 9 + 14cosθ = 0
8cos²θ+ 14cosθ + 5 = 0
let P = cosθ to have;
8P² + 14P + 5 = 0
Factorize the result
8P² + 10P + 4P + 5 = 0
2P(4P+5)+1(4P+5)=0
(2P+1) = 0 and 4P+5 = 0
2P = -1 and P = -5/4
P = -1/2 and -5/4
Recall that P = cosθ
If P = -1/2
cosθ = -1/2
θ = -60
Since cosine is negative in the second and 3rd quadrant, the required angles are 120 and 240 degrees
Learn more on trigonometry identity here: brainly.com/question/24349828
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Answer: X = -1
Solution:
2x - 6 = -8
2x = -2
X = -1
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