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Wednesday, November 28, 2012

Quadratic Formula Derivation

Category: Algebra

"Published in Newark, California, USA"

Given the quadratic equation in general form:

                          
Prove that the Quadratic Formula has a formula of 



Solution:

There are three ways in solving the quadratic equation. First,  you can solve the quadratic equation by factoring. Second, if you cannot factor the quadratic equation, you can solve it by completing the square. Third, you can solve the quadratic equation by using the Quadratic Formula. Right now, we will derive the formula for Quadratic Formula. Let's consider the quadratic equation in general form



Divide both sides of the equation by the coefficient of x2 which is a. 



Transpose the third term to the right side of the equation



Apply the completing the square method to the above equation





Get the LCD at the right side of the equation



Take the square root on both sides of the equation







Therefore,




Tuesday, November 27, 2012

Homogeneous Functions - Arbitrary Constant

Category: Differential Equations, Integral Calculus

"Published in Newark, California, USA"

Find the particular solution for 




when 

               


Solution:

If you examine the given equation, it is a differential equation because it has dy and dx in the equation. The type of equation is Homogeneous because the functions and variables cannot be separated by Separation of Variables. There's a method to solve the Homogeneous Functions. Consider the given equation



Let y = vx

    dy = vdx + xdv

Substitute y and dy to the above equation, we have











The above equation can now be separated by Separation of Variables. Arrange the equation according to their variables



Integrate both sides of the equation







Take the inverse natural logarithm on both sides of the equation



but y = vx and v = y/x







To solve for C, substitute the following:


to the above equation, we have







Therefore,



  

Monday, November 26, 2012

Dividing Rational Fractions

Category: Algebra

"Published in Suisun City, California, USA"

Perform the indicated operations and simplify



Solution:

This is a division of a rational fraction with another rational fraction. As a rule in Mathematics that we need to get the reciprocal of the divisor first and then perform the multiplication as follows





Factor all the polynomials in the numerator and denominator. Do this by trial and error so that the middle term of a polynomial is matched.



Simplify the above equation



Therefore, the answer is