The model below is made up of a cylinder and a cone
the height of the cylinder is 29cm and the height of
the cone is 19 cm - calculate the total surface area of the
model.

the reason why your question keeps getting deleted because this is not a school related question : )

i will answer your question though.

i never tried church's

, and

for

step-by-step explanation:

we can analyze the pattern at which the terms increase. let us denote , , , so that we can call

note the following:

the pattern: to get the next term value, we just add the next term number (e.g. 1st, 2nd, to the previous term value (term values are the given numbers in the question, 1, 3, 6, 10, 15,

from , to get to , we add

from , to get to , we add

etc.

we need to form a recursive formula, a formula that has the next term as a function of the previous term. so a possible recursive formula can be

, and for