Answer:
39
Step-by-step explanation:
Formula for the nth term (an) = a1 + d(n - 1) where a1 = the first term and d = common difference.
So here the 13th term = 3 + 3(13 - 1)
= 3 + 3*12
= 39 (answer).
My math teacher time me is easier to do it after
Step-by-step explanation:
the measurement or extent of something from end to end; the greater of two or the greatest of three dimensions of an object.
The radii of the frustrum bases is 12
Step-by-step explanation:
In the figure attached below, ABC represents the cone cross-section while the BCDE represents frustum cross-section
As given in the figure radius and height of the cone are 9 and 12 respectively
Similarly, the height of the frustum is 4
Hence the height of the complete cone= 4+12= 16 (height of frustum+ height of cone)
We can see that ΔABC is similar to ΔADE
Using the similarity theorem
AC/AE=BC/DE
Substituting the values
12/16=9/DE
∴ DE= 16*9/12= 12
Hence the radii of the frustum is 12
