What is the product rule's variant of the chain rule used to differentiate the composition of two functions?
+
Math question: In circle O, if two intersecting chords AB and CD have lengths 8 cm and 10 cm respectively, and their perpendicular bisectors intersect at point P, what is the length of segment OP?
+
Math question: Calculate the square root of 25, divide it by 2, subtract 3, multiply by 10, and add the sum to the square root of 16. Round the final result to the nearest whole number.