Hello, magentarita!
The cables of a suspension bridge are in the shape of a parabola.
The towers supporting the cable are 400 feet apart and 100 feet high.
If the cable is at a height of 10 feet midway between the towers,
what is the height of the cable at a point 50 feet from the center of the bridge? Place the parabola on a graph. Code:
|
(-200,100)* | *(200,100)
: | :
:* | *:
: * | * :
: * | * :
: * :
: |(0,10) :
: | :
- - + - - - + - - - + --
-200 | 200
The parabola opens upward and is symmetric to the y-axis.
. . Its general form is: . 
Its y-intercept is (0, 10) . . . Hence: . 
It passes through (200, 100).
. . We have: . 
Hence: . 
When  + 10 \:=\:\frac{125}{8})
Therefore, 50 feet from the center, the cable is
feet high.