Answer:
The length of the segment AB is 18.8 cm or 1.88 dm
Step-by-step explanation:
<u><em>The question in English is</em></u>
Points A, B and C are collinear in this order. Find the length of the segment: a) AB, if AC = 20 cm, BC = 0.12 dm
we have that
----> by Addition segment postulate
substitute the given values in centimeters
Remember that

so


solve for AB

Convert to dm

therefore
The length of the segment AB is 18.8 cm or 1.88 dm
For each <em>x</em> in the interval 0 ≤ <em>x</em> ≤ 5, the shell at that point has
• radius = 5 - <em>x</em>, which is the distance from <em>x</em> to <em>x</em> = 5
• height = <em>x</em> ² + 2
• thickness = d<em>x</em>
and hence contributes a volume of 2<em>π</em> (5 - <em>x</em>) (<em>x</em> ² + 2) d<em>x</em>.
Taking infinitely many of these shells and summing their volumes (i.e. integrating) gives the volume of the region:

Point A, point C, point B, and point E