The population of the fish is given by P(t) = 750(1 + 0.083)^t; where t is the number of years after 2005.
Here, t = 2050 - 2005 = 45
Population in 2050 = 750(1.083)^45 = 750(36.16) = 27,123
Answer:
- x = log(y/4)/log(1.0256)
- your answer for y=12 is correct
Step-by-step explanation:
The question is asking you to solve ...
y = f(x)
for x. (In other words, find the inverse function.)
You already did this using a constant for y. Do the same thing with y instead of the constant.
y = 4(1.0256^x)
y/4 = 1.0256^x . . . . . . . divide by 4
log(y/4) = x·log(1.0256) . . . . . take logs
log(y/4)/log(1.0256) = x . . . . . divide by the coefficient of x
Now, you have a model for x in terms of y, which is what the question is asking for.
x = log(y/4)/log(1.0256) . . . . . . . exact expression
When y=12, this is ...
x = log(12/4)/log(1.0256) ≈ 43.46 . . . . weeks
_____
This is a linear equation in log(y), so can be written as such:
x = 91.0912·log(y) -54.8424 . . . . . approximate expression
First step: name the sides according to geometry standards, namely, the sides are named the same lowercase letter as the opposing angle. A revised diagram is shown.
Second step: we need to know the relationships of the trigonometric functions.
cosine(A)=cos(63) = adjacent / hypotenuse = AC/AB .................(1)
sine(A)=sin(63) = opposite / hypotenuse = CB/AB .......................(2)
We're given AB=7, so
using (1)
AC/AB=cos(63)
AC=ABcos(63)=7 cos(63) = 7*0.45399 = 3.17993 = 3.180 (to three dec. figures)
Using (2)
BC/AB=sin(63)
BC=ABsin(63) = 7 sin(63) = 7*0.89101 = 6.237 (to three dec. figures).
