Answer:
30m
Step-by-step explanation:
A=πr²
225π=πr²
225=r²
r=√225
r=15
d=2r
d=2×15
=30m
Answer:

Step-by-step explanation:
It is a linear homogeneous differential equation with constant coefficients:
y" + 4y = 0
Its characteristic equation:
r^2+4=0
r1=2i
r2=-2i
We use these roots in order to find the general solution:

For this problem, you would replace x with 7 then solve.
3/ (7+2) - sqrt(7-3) =
3/9 - sqrt(4) =
1/3 - 2 = -1 2/3 = -1.67
f(7) = 1