Answer:
30
Because the leaf and root are not sex organ
Star brightness is defined by either <span>D. apparent magnitude - when we measure it from Earth (that is how bright it is from Earth) - this is the closest to "basic observation" and the best answer
or by absolute magnitute - how bright it would be at a certain distance (this allows to compare the brightness).
</span>
On site means insitu.
invitro means in glass like a test tube.
We need to show that y = x/(x + c) is a solution of dy/dx = (y - y^2)/x. Then,
<span>dy/dx = ((x + c) * 1 - x * 1)/(x + c)^2 </span>
<span>= (x + c - x)/(x + c)^2 </span>
<span>= c/(x + c)^2 </span>
<span>and </span>
<span>(y - y^2)/x = (x/(x + c) - x^2/(x + c)^2)/x </span>
<span>= (x(x + c) - x^2)/(x(x + c)^2) </span>
<span>= (x^2 + cx - x^2)/(x(x + c)^2) </span>
<span>= cx/(x(x + c)^2) </span>
<span>= c/(x + c)^2 </span>
<span>which proves the equality. </span>