Answer:
Step-by-step explanation:
We want to model the position of the submarine as a function of time.
Notice that we have a constant amount. The initial depth: 750 meters
Then we have a factor that varies over time. Every hour the submarine ascends 50 meters. therefore as t increases the depth y(t) of the submarine decreases. Then the factor is:
-50t.
Where t represents the time in hours.
Then the equation that represents the new position of the submarine in relation to the level of the sea:
Some things you need to know:
1) You need to know how to convert standard form to slope y-int. form and slope y-int. form to standard form.
2) When two lines are parallel, the slopes are the same.
3) When two lines are perpendicular, the slopes are negative reciprocals of each other. (Or their product is -1)
example: 3/4 --> -4/3.
3/4 * -4/3 = -12/12 = -1
4) To find the value of b, substitute the point into the equation.
5) Convert the equation to slope y-int. form to find the slope.
6) When a line has an undefined slope, the slope y-int. will look either like
y = __ (forms horizontal line) or x = __ (forms vertical line).
To find the perpendicular of these lines, turn y to x / x to y.
To find the value of __, look at the point located in the line, so if x = ___
passes through (5,3), then x = 5 because x = 5 in the point. So the
equation would be x = 5.
Use online practice tests and other sources if you don't understand.
Answer:
-81t^2 +16
Step-by-step explanation:
(9t-4)(-9t-4)
FOIL
first: -9t*9t = -81t^2
outer : -4*9t = -36t
inner : -4 *-9t = 46t
last = -4*-4 = 16
Add them together
-81t^2 -36t+36t+16
-81t^2 +16
