If there is an error of a% in measuring the edge of a cube, then percentage error in its surface is 2a% (b) `a/2%` (c) `3a %` (d) none of these

Explanation

let x be the edge of cube

`(dx)/x xx 100 = a`

surface area of cube , `s= 6x^2`

diff wrt x

`(ds)/(dx) = 12x`

`(ds)/s xx 100 = ( 12x xx dx)/(6x^2) xx 100`

`= (12x xx (ax)/100)/(6x^2) xx 100`

`= (12ax^2)/(6x^2 xx 100) xx 100`

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