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The height (h) of water flowing out of a tank decreases at a rate proportional to the square root of the height of water still in the tank. If h=9 at t=0 and h=4 at t=5, what is the water’s height at t=15? What is the physical interpretation of this?

Note: time, t, is measured in minutes, and height, h, is measured in metres. Let k>0, a constant. The differential equation to be solved is given by: dh/dt = - k(h)^0.5. Using 'separation of variables' gi...
SN
Answered by Sandie N. • Maths tutor
5915 Views

curve C with parametric equations x = 4 tan(t), y=5*3^(1/2)*sin(2t). Point P lies on C with coordinates (4*3^(1/2), 15/2). Find the exact value of dy/dx at the point P.

dy/dx = dy/dt *dt/dx (chain rule). x=4tan(t) hence dx/dt = 4 sec 2 (t) y = 5 3 1/2 sin(2t) hence y'= 10 3 1/2 cos(2t) therefore dy/dx = 10 3 1/2 cos(2t) / 4 sec 2 (t). Since P is on point with x=4 3 1/2 we c...
HP
Answered by Harry P. • Maths tutor
8481 Views

Find the first derivative of r=sin(theta+sqrt[theta+1]) with respect to theta.

To find the first derivative we must apply the chain rule. Our aim is to find dr/d(theta). We start by bringing the differential of what's inside the sine brackets outside and multiplying it by the different...
TD
Answered by Tutor61926 D. • Maths tutor
5201 Views

Perhaps an introduction to integration with a simple integral, e.g. the integral of x^2

I would first write out the integral with correct notation, explaining to my tutee exactly what I am drawing and why. I will then explain the 'n+1' rule for integrating simple powers. I will go through the i...
RC
Answered by Reece C. • Maths tutor
3675 Views

Find, in radians, the general solution of the equation cos(3x) = 0.5giving your answer in terms of pi

we have cos (3x) = 0.5 (1) we know that in the interval between [-pi; pi] there are two values that satify the equation cos(y) = 0.5 (2) the two solutions are y=pi/3 and y=-pi/3 in this interval. More genera...
MB
Answered by Marie B. • Maths tutor
7788 Views