Top answers


Find the general solution of the differential equation d^2y/dx^2 - 2(dy/dx) = 26sin(3x)

2 Parts to this question - requires a complimentary function (treating equation as if right-hand side (RHS) = 0) and a particular integral (the general solution for where the RHS = 26sin(3x) ) 1) The complim...
MP
6204 Views

A tank contains 500L of salty water. Pure water is pumped in at a rate of 10 L/sec, and the the mixture is pumped out at a rate of 15L/ sec. If the concentration of salt is 5g/L initially, form an equation of amount of salt, s, at t seconds.

This is a word problem with the task of forming a first order differential equation (or DE), and involves two major aspects that need to be worked out: the volume of water in the tank at any given point, and...
3796 Views

Find the volume of revolution about the x-axis of the curve y=1/sqrt(x^2+2x+2) for 0<x<1

The volume of revolution is given by integrating Pi y 2 dx from 0 to 1.Squaring, y 2 =1/(x 2 +2x+2)Completing the square, we see that y=1/((x+1) 2 +1)Make the substitution u=x+1, so du=dx. When x is 0, respe...
HG
2999 Views

Particles P and Q move in a plane with constant velocities. At time t = 0 the position vectors of P and Q, relative to a fixed point O in the plane, are (16i - 12j) m and -5i + 4j) m respectively. The velocity of P is (i + 2j) m/s and the velocity of Q

is (2i + j) m/s. Find the shortest distance between P and Q in the subsequent motion. This is an m4 question from the edexcel June 2015 paper. First I would explain to the student that I would form an equati...
3052 Views

For what values of x is Cosh^2(x) - Sinh(x) = 5 Give your answer in the form of a logarithm

Substitute Cosh^2(x) = 1 + Sinh^2(x) into the starting equation (This formula should be known)Make 0 the subject 3Sinh^2(x) - Sinh(x) - 2 = 0Substitute u = Sinh(x) and solve for uSubstitute Sinh(x) back in f...
LB
3054 Views