Question

Question #606a2

Answer 1

I found: `(dA)/(dt)=-27(cm^2)/s`

Explanation:

When `A=27sqrt(3)cm^2` then using (1) `A=sqrt(3)/4l^2` you get:
`27sqrt(3)=sqrt(3)/4l^2`
`color(red)(l=10.4cm)`
Now you use (2) and get the change in the area as:
`(dA)/(dt)=2sqrt(3)/4xx(10.4)xx(-3)=-27(cm^2)/s`

Answer 2

`27` cm^2/s

Explanation:

`A = (1/2) a*a*sin60 =( (sqrt3)/4)a^2`

`(dA)/dt = ( (sqrt3)/2)a((da)/dt)`

If `A = 27(sqrt3`) => `a = 6(sqrt3)`

Then, `(dA)/dt =( (sqrt3)/2)6(sqrt3)(3) " cm^2/s" = 27 " cm^2/s"`