Solutions of First Order, First Degree Ordinary Differential Equation Homogeneous Differential Equation Lecture
Method 2: Homogeneous Differential Equation 29 August 2024 Prepared By: Engr. Ma. Cristina Macawile 2 Standard Form M (x, y) dx + N ( x,y ) dy = 0 where M ( x,y ) and N( x,y ) dy are homogeneous functions in the same degree The equations can be reduced to variable separable by using the following substitutions Let
29 August 2024 Prepared By: Engr. Ma. Cristina Macawile 3 Definition of a homogeneous function F ( x,y ) is said to homogeneous if , F ( x , y) = F k ( x,y ) That is if x and y are simultaneously replaced by x and y , the original function multiplied by k results. k – being the degree of homogeneity
29 August 2024 Prepared By: Engr. Ma. Cristina Macawile 4 Direction : Determine if the function is homogeneous. Determine the degree of homogeneity Sample 1 : F (x, y) = Step 1: Replace all ‘x’ by x and ‘y’ by y F ( x , y) = = Step 2: Factor out the ‘ ‘ F ( x , y) = ( F k ( x,y ) = ( Step 3: Identify the value of k. F ( x,y ) is said to homogeneous if , F ( x , y) = F k ( x,y ) k = 2 , the function is homogeneous , 2 nd degree
29 August 2024 Prepared By: Engr. Ma. Cristina Macawile 5 Sample 2. F (x, y) = Step 1: Replace all ‘x’ by x and ‘y’ by y F ( x , y) = = Step 2: Factor out the F k ( x,y ) = Step 3: Identify the value of k. F ( x,y ) is said to homogeneous if , F ( x , y) = F k ( x,y ) k = 4 , the function is homogeneous , 4 th degree
29 August 2024 Prepared By: Engr. Ma. Cristina Macawile 6 Determine if homogeneous or nonhomogeneous. If homogeneous, determine the degree. F (x, y) = 2. F ( x,y ) =
29 August 2024 Prepared By: Engr. Ma. Cristina Macawile 7 Homogeneous Differential Equation Sample 1: Solve for general solution Step 1: Check if homogeneous, if yes proceed. Homogeneous , degree 2 Step 2: Replace x = , or y = , ( = 0
29 August 2024 Prepared By: Engr. Ma. Cristina Macawile 8 Step 3: Simplify and combine similar terms. ( = 0 =0
29 August 2024 Prepared By: Engr. Ma. Cristina Macawile 9 Step 4: Perform variable separable method. Multiply the equation by . (
29 August 2024 Prepared By: Engr. Ma. Cristina Macawile 10 Step 5: Back substitute the . Write the general solution This is from the previous representation, x = . General Solution
29 August 2024 Prepared By: Engr. Ma. Cristina Macawile 11 Sample 2: Solve for general solution and particular solution. x = 1, y = Step 1: Check if homogeneous, if yes proceed. Homogeneous, degree 1 Step 2: Replace y = , or x = , For this example we choose, y = ,
29 August 2024 Prepared By: Engr. Ma. Cristina Macawile 12 Step 3: Simplify and combine similar terms. Step 4: Perform variable separable method. Multiply the equation by .
29 August 2024 Prepared By: Engr. Ma. Cristina Macawile 13 Step 5: Back substitute the to solve for general solution . This is from the previous representation, y = . Write the general solution Step 6: Substitute values of x and y to solve for particular solution General Solution Particular Solution
29 August 2024 Prepared By: Engr. Joshua Hernandez 14
29 August 2024 15 Prepared By: Engr. Ma Cristina Macawile