Answer:
8 feet
Step-by-step explanation:
the length still remains the same regardless of the scale
<h3>Answer: 7 goes in the blank space</h3>
The range of values for x is 2 < x < 7
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Explanation:
The hinge theorem says that the larger the opposite side is, the larger the angle will be.
AD = 11, DC = 8
Since AD > DC, this means angle ABD > angle DBC.
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angle ABD > angle DBC
20 > 4x-8
20+8 > 4x-8+8 ... add 8 to both sides
28 > 4x
4x < 28 ... flip both sides and the inequality sign
4x/4 < 28/4 ... divide both sides by 4
x < 7
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At the same time, the angle 4x-8 cannot be 0 or negative.
So we say 4x-8 > 0. Let's solve this for x.
4x-8 > 0
4x-8+8 > 0+8 ... add 8 to both sides
4x > 8
4x/4 > 8/4 ... divide both sides by 4
x > 2
2 < x ... flip both sides and the inequality sign
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We have 2 < x and x < 7. Both of these combine to the compound inequality 2 < x < 7
We can pick any value between 2 and 7 as long as we dont pick x = 2 or we dont pick x = 7.
tan2x*cotx - 3 = 0
We know that: tan2x = sin2x/cos2x and cotx = cosx/sinx
==> sin2x/cos2x *cosx/sinx = 3
Now we know that sin2x = 2sinx*cosx
==> 2sinxcosx/cos2x * cosx/sinx = 3
Reduce sinx:
==> 2cos^2 x/ cos2x = 3
Now we know that cos2x = 2cos^2 x-1
==> 2cos^2 x/(2cos^2 x -1) = 3
==> 2cos^2 x = 3(2cos^2 x -1)
==> 2cos^2 x = 6cos^2 x - 3
==> -4cos^2 x= -3
==> 4cos^2 x = 3
==> cos^2 x = 3/4
==> cosx = +-sqrt3/ 2
<span>==> x = pi/6, 5pi/6, 7pi/6, and 11pi/6</span>
