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4 votes
4 votes
A tunnel has a parabolic cross-section. It is 24m wide at the base. At a point 6m above the base, the width is 18m. Find the maximum height of the tunnel

User Grigoryants Artem
by
2.6k points

1 Answer

16 votes
16 votes

Answer:

13.71 m

Explanation:

Draw the tunnel so the width marks the zeroes at (-12,0) and (12,0)

then y = a ( x+12)(x-12) is the equation..

..to calculate 'a' sub in the point 9, 6 (where the width is 18)

6 = a ( (9+12)(9-12) shows a = -2/21

y = -2/21 (x+12)(x-12) Max is when x = 0

-2/21 ( 12)(-12) = 288/21 = 13.71 m

User Cyberfly
by
2.6k points
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