IIT JEE , AIEEE Forum - Mathematics , Differential Calculus

rags

i have a doubt.
if
f(x)=x^{2.
d/dx f(x)=2x.

but}f(x)=x².can be written as
f(x)=(x+x+x...x times)
d/dx f(x)=(1+1+1..x times)
=x.
so y are the two answers differnt?

puneet

hey

well ..

yaar .. x + x + x ... x time .... right .. now this x times is not a constant .. and ths the approach that u follwed cannot be used ..

cheers

kuldud

xcuse me dear if f(x)= x^2
then how it is equal to (x+x+x+.....) ???
btw way x is not a constant so it cant b x
dis approach is not right

priyesh

x^2 = x+x+x+x+......x times only if x is a positive integer

but f(x)= x^2 is a continous function

so when we put the condition on x that it should be an integer the graph becomes discontinuous & non differentiable.(as function will now attain only integral values).

hence we cannot find dy/dx.

cutepooja

i dun wether i am correctbut see
try to analyse the case
f(x)=x2.
d/dx f(x)=2x.this is ok but only for x on real no line

(x)=x2.can be written as
f(x)=(x+x+x...x times)
d/dx f(x)=(1+1+1..x times)
=x.
here there is a mistake this holds good only for natural no and then the function f(x) becomes discont so how can u find derivative
ya its ame as priyesh

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