Tess tried to solve the differential equation dxdy=2xy−6x. This is her work:dxdy=2xy−6xStep 1: dxdy=(y−3)2xStep 2: ∫y−31dy=∫2xdxStep 3: ln∣y−3∣=x2+C1Step 4: eln∣y−3∣=ex2+C1Step 5: ∣y−3∣=ex2+C1Step 6: y−3=±ex2+C2Step 7: y=±ex2+CIs Tess's work correct? If not, what is her mistake?Choose 1 answer:(A) Tess's work is correct.(B) Step 1 is incorrect. We're not allowed to factor an expression when solving differential equations.(C) Step 4 is incorrect. The right-hand side of the equation should be ex2+C1.(D) Step 7 is incorrect. Tess didn't account for adding 3 to the right side.
Q. Tess tried to solve the differential equation dxdy=2xy−6x. This is her work:dxdy=2xy−6xStep 1: dxdy=(y−3)2xStep 2: ∫y−31dy=∫2xdxStep 3: ln∣y−3∣=x2+C1Step 4: eln∣y−3∣=ex2+C1Step 5: ∣y−3∣=ex2+C1Step 6: y−3=±ex2+C2Step 7: y=±ex2+CIs Tess's work correct? If not, what is her mistake?Choose 1 answer:(A) Tess's work is correct.(B) Step 1 is incorrect. We're not allowed to factor an expression when solving differential equations.(C) Step 4 is incorrect. The right-hand side of the equation should be ex2+C1.(D) Step 7 is incorrect. Tess didn't account for adding 3 to the right side.
Factorize right-hand side: Tess starts by factoring the right-hand side of the differential equation.dxdy=2xy−6xdxdy=2x(y−3)This is a correct step as factoring is allowed and can be useful in solving differential equations.
Separate variables for integration: Tess separates the variables to each side of the equation to integrate.∫y−31dy=∫2xdxThis is a correct step in solving separable differential equations.
Integrate both sides: Tess integrates both sides of the equation.ln∣y−3∣=x2+C1The integration is done correctly, with C1 being the constant of integration for the right-hand side.
Exponentiate to solve for y−3: Tess exponentiates both sides to solve for ∣y−3∣.eln∣y−3∣=ex2+C1This step is incorrect. The right-hand side should be exponentiated as a whole, including the constant C1.