Use the method of disk or washer to set up, but do not evaluate, an integral for a volume of the solid obtained by rotating the region bounded by the given curves about the given line. y=√x and y=x and y=1

V =  π /2   volume units

Step-by-step explanation:

Volume of    y = √x   bounded by  y = x   and y = 1

y = √x

limits of integration   ( see Annex )

By simple inspection limits of integration are   x = 0    to  x = 1

or  y = √x     and    y = x

solving these two equations

x = 0    y = 0       x = 1      y = ± 1

V = ∫ π*f(x)²*dx    

V  =  π * ∫₀¹ x*dx   =    π * x²/2 |₀¹

V =   π * (1/2) - 0

V =  π /2   volume units

7

step-by-step explanation:

, 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