http://www.shelovesmath.com/precal/conics/
I chose this problem because it shows an example of how math that we learn, like graphing and plotting points, can be used to wire cables on a bridge. Wires on a bridge insure that the bridge doesn't collapse and that it is safe to cross. Many architects have to use calculus to make sure that structures are built correctly, so they are safe to cross and don't collapse. Bridges have to be able to support a lot of weight which is why architects have to put wires across the bridge at certain points. This problem uses the given distance of the two towers to try and find the height of the cable and how far it should be from the center. The problem first finds the equation of the parabola by plugging in the points given and then it plugs in the height to find the distance from the center. The distance had be calculated because you need to make sure that all the wires are equidistant from the center. This makes sure the bridge is stable and safe to cross.

https://www.slideshare.net/TuhinAhmed7/calculus-in-real-life-differentiation-and-integration
The solution and work is on slides 8 and 9. I chose this problem because it has never occurred to me that police would ever need to use calculus. I have always though of architects and engineers, but never even considered that other fields could use math. This problem uses substitution and logarithmic functions to determine time of death. The detective used the body temperatures of the rooms and victim's body and then plugged those numbers into two equations. Then the substitution was applied and logs were used. It is very cool to find out that the time of death can be determined through calculus and body temperature.