- #1
NatFex
- 26
- 3
I'm a bit iffy with the whole of the 'related rates' topic of my calculus course. I've tried coming up with a question of my own to see if I can solve it. The question is as follows:
The distance between a point on the ground and the bottom of a pole is 26m. The angle of inclination from that point to the top of the pole is increasing at 4ºs-1. What is the rate of change of the distance between that point and the top of the pole?
(Note that the answer would be an expression and not a number.)
So it took me a lot longer than I was expecting and I got stuck a few times, but here's what I got. So if the triangle is PBT where PT is the side you have to find the rate for, then I get:
##{\frac {d(PT)}{dt}} ={\frac {4*\sqrt{1-({\frac {26}{PT}})^2}*PT^2}{26}}##
However obviously since this question is my own composition I can't compare it against a mark scheme or anything, can anyone confirm that I've done this correctly? Happy to provide working upon request.
The distance between a point on the ground and the bottom of a pole is 26m. The angle of inclination from that point to the top of the pole is increasing at 4ºs-1. What is the rate of change of the distance between that point and the top of the pole?
(Note that the answer would be an expression and not a number.)
So it took me a lot longer than I was expecting and I got stuck a few times, but here's what I got. So if the triangle is PBT where PT is the side you have to find the rate for, then I get:
##{\frac {d(PT)}{dt}} ={\frac {4*\sqrt{1-({\frac {26}{PT}})^2}*PT^2}{26}}##
However obviously since this question is my own composition I can't compare it against a mark scheme or anything, can anyone confirm that I've done this correctly? Happy to provide working upon request.