The first thing we must do in this case is find the derivatives:
y = a sin (x) + b cos (x)
y '= a cos (x) - b sin (x)
y '' = -a sin (x) - b cos (x)
Substituting the values:
(-a sin (x) - b cos (x)) + (a cos (x) - b sin (x)) - 7 (a sin (x) + b cos (x)) = sin (x)
We rewrite:
(-a sin (x) - b cos (x)) + (a cos (x) - b sin (x)) - 7 (a sin (x) + b cos (x)) = sin (x)
sin (x) * (- a-b-7a) + cos (x) * (- b + a-7b) = sin (x)
sin (x) * (- b-8a) + cos (x) * (a-8b) = sin (x)
From here we get the system:
-b-8a = 1
a-8b = 0
Whose solution is:
a = -8 / 65
b = -1 / 65
Answer:
constants a and b are:
a = -8 / 65
b = -1 / 65
The information's given in the question are of vital importance. These information's should be very useful while getting to the desired answer of the given question.Let us now concentrate on the problem that needs to be solved.
The height of the sign that casts a shadow of 4 meters is = 5 meters
Then
The height of the tree that casts a shadow of 30 meters = (5/4) * 30 meters
= 150/4 meters
= 37.5 meters
So the tree casting a shadow of 30 meters is actually 37.5 meters in height. I hope the procedure is simple enough for you to understand.
So 4 inches diameter result the radius is 4/2 = 2 inches
area of base = pir^2 = 3,14*2^2 = 3,14*4 = 12,56 inches squared
volume = area of base *height
V = 12,56 *9 = 113,04 so rounded 113,05 inches cubed
hope this will help you
The first President of the Czech Republic was Václav Havel
