Fabio is designing a flashlight that uses a parabolic reflecting mirror and a light source. The shape of the mirror can be model
2 answers:
You might be interested in
Answer:
Correct choice is A
Step-by-step explanation:
Two vertices of the rectangle have coordinates A(-1, 5) and B(2, 1). If rectangle sides are parallel to the axes, then two remaining vertices have coordinates C(-1,1) and D(2,5) (see attached diagram for details).
Find the length and the width:
Then the length is 1 unit longer than the width.
Answer:
This situations represents the depth of the lake after t years.
The rate of decay is equal to 0.02 a year.
So the depth of the lake each year is 0.98 times the depth in the previous year.
It will take 5.77 years for the depth of the lake to reach 26.7 meters.
Step-by-step explanation:
Exponential equation of decay:
The exponential equation for the decay of an amount is given by:
In which D(0) is the initial amount and r is the decay rate, as a decimal.
A lake currently has a depth of 30 meters. As sediment builds up in the lake, its depth decreases by 2% per year.
This means that
So
This situation represents
The depth of the lake after t years.
The rate of growth or decay, r, is equal to
The rate of decay is equal to 0.02 a year.
So the depth of the lake each year is times the depth in the previous year.
1 - 0.02 = 0.9
So the depth of the lake each year is 0.98 times the depth in the previous year.
It will take between years for the depth of the lake to reach 26.7 meters.
This is t for which D(t) = 26.7. So
It will take 5.77 years for the depth of the lake to reach 26.7 meters.