# math

posted by
**David**
.

How do I take the partial derivative of P with respect to r of the following:

D × P = ∑(t=1 to T)[t × (CF)_t/(1+r)^t ]

posted by
**David**
.

How do I take the partial derivative of P with respect to r of the following:

D × P = ∑(t=1 to T)[t × (CF)_t/(1+r)^t ]