Which of the following functions describes the sequence 1, 3, 7, 15, 31, 63, 127, … ?

A. f(1) = 1,f(n) = f(n − 1) + n for n > 1.
B. f(1) = 1,f(n) = 2n + 1 for n > 1.
C. f(1) = 1,f(n) = f(n − 1) + 2(n − 1) for n > 1.
D. f(1) = 1,f(n) = 2f(n − 1) + 1 for n > 1.

What effect would doubling all the dimensions of a triangular pyramid have on the volume of the pyramid? explain your reasoning.

Having a hard time understanding this question (see attachment).

Use the following statements to write a compound statement for the conjunction or disjunction. then find its truth value. p: an isosceles triangle has two congruent sides. q: a right angle measures 90° r: four points are always coplanar. s: a decagon has 12 sides. a) a right angle measures 90° or an isosceles triangle has two congruent sides; true. b) a right angle measures 90° and an isosceles triangle has two congruent sides; true. c) a right angle measures 90° and an isosceles triangle does not have two congruent sides; false. d) a right angle measures 90° or an isosceles triangle does not have two congruent sides; true.