rates of change (1 Viewer)

[blakwidow]

Show that in an equilateral triangle of side length s, the area is given by

A = s²/4rt3 and the hieght by h = s/2 rt 3

a)Find the formuale for the rates of change of area and height.

answer has dA/dt = ....... and dH/dt = ....

but what does time have to do anything with this question?

 

[PC]

A rate of change is a change with respect to time. That's why you'll see dA/dt and dh/dt in the answers.

With what you've given us there's not really any information about any time aspect in the question. Does your question say something about the sides of the triangle increasing at a certain rate?

If so, then that's the value of ds/dt, the change in s with respect to time.

Then, by the chain rule:
dA/dt = dA/ds x ds/dt
dh/dt = dh/ds x ds/dt

For the record, dA/ds = (√3 s)/2 and dh/ds = (√3)/2.

Hope this helps.

 

[blakwidow]

oh ok.

part b) has something to do with time but nothing about time on part a)

thanks anyways

bye

p.s posted another qn in ext 1 forum