Answer:
7536 
Step-by-step explanation:
Given that:
Rate of decreasing of radius = 12 km/sec
Height of cylinder is fixed at = 2.5 km
Radius of cylinder = 40 km
To find:
The rate of change of Volume of the cylinder?
Solution:
First of all, let us have a look at the formula for volume of a cylinder.
Where 
is the radius and
is the height of cylinder.
As per question statement:
= 40 km (variable)
= 2.5 (constant)
As 
are constant:
Answer:
The numbers should be A. 5 and C. 0.
Hope I Helped
Answer:
<h2>11.72cm</h2>
Step-by-step explanation:
Given a chord of distance of 15cm, if it is 9cm from the center of a circle, this means that the 9cm length will be projecting from the centre of the circle perpendicular to the chord and passing through its centre.
Since the radius of a circle is a line that is drawn from the centre of a circle to ts circumference, the set up will form a right angles triangle within the circle with the hypotenuse as the radius and the other two sides as the opposite and adjacent respectively. Using the Pythagoras theorem to get the length of the radius (hypotenuse);
hyp² = opp² + adj²
Let the opposite be the 9cm length
Adjacent will be half of the chord length = 15/2 = 7.5cm
Substituting this values into the formula we will have;
hyp² = 9² + 7.5²
hyp² = 81+56.25
hyp² = 137.25
hyp² = √137.25
hyp = 11.72
<em></em>
<em>Hence the radius of the circle is approximately 11.72 cm long</em>
Hello!
Answer:
x=7(a+y)
Step-by-step explanation:
Hope this helps!
Answer:
1/sqrt10
Step-by-step explanation:
1) Find out cosA using formula (cosA)^2+(sinA)^2=1
The module of cosA= sqrt (1- (-3/5)^2)= sqrt 16/25=4/5
So cosA=-4/5 or cosA=4/5.
Due to the condition 270degrees< A<360 degrees, 0<cosA<1 that's why cosA=4/5.
2) Find sinA/2 using a formula cosA= 1-2sinA/2*sinA/2 where cosA=4/5.
(sinA/2)^2= 0.1
sinA= sqrt 0.1= 1/ sqrt10 or sinA= - sqrt 0.1= -1/sqrt10
But 270°< A< 360°, then 270/2°<A/2<360/2°
135°<A/2<180°, so sinA/2 must be positive and the only correct answer is
sin A/2= 1/sqrt10
