What is R and how is it related to r? Convention dictates that variables are case sensitive
If R is some constant:
where
edit: you can check integration by differentiating the result and since it's not correct
Sorry Ill explain myself better. The question relates to charge distribution that is spherically symmetrical. This charge distribution is over the range:
A(1 - r/R) for r< R
and
0 for r > R
Where A is a constant
Making a few assumptions about the charge distribution we get:
Q = A( 1 - r/R) × 4πr^2* δr = 4πA(1 - r^3/R)δr
π = pi
So to find the total charge over the whole of sphere we take integral from R to 0:
Q = 4πA(1 - r^3/R) = 4πA [This is the bit i am obviously getting wrong!] = ??????
Sorry about using the correct symbols but i don't seem to be able to cut and paste from word into the forum