help with a rate of change qn 10 pts?
The perimeter of a circular sector is 30cm.
(I) Write down an equation relating the radius and angle of the sector.
(II) The radius increases at a rate of 5cm/s^-1. Find the rate at which the angle of the sector is changing when the radius is 10cm.
Do explain it step by step because it is a new topic to me.
Thank you but I need help with part ii as well :/
- icemanLv 78 years agoFavorite Answer
The perimeter of a sector is the sum of the arc length i.e: s and two radii, so:
P = s + 2 r , but:
s = r θ , so:
P = r(θ + 2)
in this case:
r(θ + 2) = 30 cm
r = 30/(θ + 2)