Ying is a professional deep water free diver.

His altitude (in meters relative to sea level), xxx seconds after diving, is modeled by:

D(x) 1/36(x-60)^2-100
How many seconds after diving will Ying reach his lowest altitude?

60 seconds

Step-by-step explanation:

In this problem, the altitude of Ying at time x is given by the equation

where

x is the time in seconds

D is the altitude above sea level, in meters

Here we want to find the time x' at which Ying reach his lowest altitude. This means that we have to find the minimum of the function D(x). In order to do that, first we rewrite the function as

This is an upward parabola, written in the form:

We know that the minimum of an upward parabola corresponds to its vertex, which has x-coordinate of

(1)

In this case,

Substituting into (1), we find

So, the minimum of D(x) occurs at x = 60: therefore, Ying reaches his lowest altitude after 60 seconds.

i can answer this question sweetie!

step-by-step explanation:

step-by-step explanation:

ok so im not 100% sure but you would start by adding 5.1t and 1.9t beacuse they have the same variable. that is 7t.   then add -3.6 + 1.2 which is -2.4

so then keep that as -2.4 + 7t. i apologize if this is incorrect. best luck on your test < 3