A circular metal plate expands under heating so that its radius increases by k%. Find the approximate increase in the area of the plate, if the radius of the plate before heating is 10 cm.

Explanation

Hecne, We have `x=10` and

`Δx=k/100xx10`

`Δx=0.1k`

`text(Area)=πx^2`

On differentiating Area wrt `x`, We get

`(dA)/(dx)=d/(dx)πx^2`

`dA/dx=πd/(dx)x^2`

We know,

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