Answer:
x² + (y + 8)² = 81
Step-by-step explanation:
Centre (h,k) = (0,-8)
radius (r) = 9
(x - h)² + (y - k)² = r²
(x - 0)² + (y + 8)² = 9²
x² + (y + 8)² = 81
An expression that is equivalent to 2.3 x 2.3 x 2.3 x 2.3 x 2.3 is 2.3^
First: the homogeneous solutions: the characteristic equation is4r^2 - 4r - 3 = 0which has roots r = 3/2, -1/2 hence the homogeneous solution isy = c1.exp(-x/2) + c2.exp(3x/2)
next you need the general form for the guess for yp and that isyp = A1cos(2x) + A2sin(2x)
Now substitute that into the equation and solve for A1, A2.
The function:
f ( x ) = x * 0.965^t
where x is the initial amount and t is the number of the years
80 = x * 0.965^3
80 = x * 0.89632
x = 80 : 0.89632 ≈ 89
Answer:
The initial amount of animals was 89.
Hope this helps!
Have a nice day :)
His mistake was on step 1
