A 9-
From the top of a 25 m high cliff, the angle
of depression of a jet ski at point A is 20°.
The jet ski moves in a straight line towards
the base of the cliff so that its
angle of depression 5 s later
at point B is 30°.
a Calculate the distance AB.
b Find the average speed of
the jet ski in kilometres/hour.

step-by-step explanation:

once you graph it hit 2nd (the blue button) and graph

that takes you to a table of coordinates

on the left is x coordinates and on the right is y coordinates and an empty box

(you may have to scroll up/down in order to get ( x, 0)

, 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

answer: your answer is c

step-by-step explanation: