Free counters!

Monday, December 30, 2013

Solving Logarithmic Equation, 3

Category: Algebra, Trigonometry

"Published in Newark, California, USA"

Solve for x:


Solution:

Consider the given equation above


Did you notice that the bases of the logarithmic functions are different? Well, we have to convert all the logarithmic functions into the same base first. Let's convert all the logarithmic functions into base 2 as follows

for


for


for


Hence, the given equation becomes






Take out their common factor, we have



Since the terms inside the bracket are all coefficients, then we can eliminate the coefficient since the right side of the equation is zero.



Take inverse logarithm on both sides of the equation




Take inverse tangent on both sides of the equation




Therefore, the answer is


I would like to thank Mr. Bilomba Nkita Leonard, Educator of Mathematics and Physical Sciences at Northwest Department of Education in South Africa who posted this problem at LinkedIn. 

Sunday, December 29, 2013

Solving Equations - Homogeneous Functions, 2

Category: Differential Equations, Integral Calculus

"Published in Newark, California, USA"

Find the general solution for


Solution: 

Consider the given equation above


Did you notice that the given equation cannot be solved by separation of variables? The first term is a combination of x and y in the group and there's no way that we can separate x and y. 

This type of differential equation is a homogeneous function. Let's consider this procedure in solving the given equation as follows


Let


so that


Substitute the values of y and dy to the given equation, we have








The resulting equation can now be separated by separation of variables as follows



Integrate on both sides of the equation, we have




But



Hence, the above equation becomes






Therefore, the general solution is

 

Saturday, December 28, 2013

Variable Separation, 6

Category: Differential Equations, Integral Calculus

"Published in Newark, California, USA"

Find the general solution for 


Solution:

Consider the given equation above


Transpose xy to the right side of the equation, we have



Arrange the above equation by separation of variables, we have




Integrate on both sides of the equation, we have










Take the inverse natural logarithm on both sides of the equation




where K = eC. Therefore, the general solution is