`x = 2` पर फलन ` f(x) = 3x` का अवकलज ज्ञात कीजिए ।

Explanation

` :' x = a "पर "f(x) " का अवकल "`
` f'(a) = lim _( h to 0) (f(a+h)-f(a))/h`
यहाँ `f (x) = 3x`
`a=2`,
` :. f'(2+h) = 3 ( 2 +h) = 6 + 3h`
तथा ` f(2) = 3 xx 2 = 6 `
` :. f'(2) = lim _( h to 0 ) ( 6+3h-6)/h`
` = lim _( h to 0 ) (3h)/h = lim _( h to 0 ) 3=3`