Lara tried to solve the differential equation dxdy=xy+2x. This is her work:dxdy=xy+2xStep 1: dxdy=x(y+2)Step 2: ∫(y+2)−1dy=∫xdxStep 3: ln∣y+2∣=2x2+C1Step 4: eln∣y+2∣=e2x2+C1Step 5: ∣y+2∣=e2x2eC1Step 6: y+2=Ce2x2Step 7: y=Ce2x2−2Is Lara's work correct? If not, what is her mistake?Choose 1 answer:(A) Lara's work is correct.(B) Step 1 is incorrect. We're not allowed to factor an expression when solving differential equations.(C) Step 2 is incorrect. The separation of variables wasn't done correctly.(D) Step 4 is incorrect. The right-hand side of the equation should be e2z2+C1.
Q. Lara tried to solve the differential equation dxdy=xy+2x. This is her work:dxdy=xy+2xStep 1: dxdy=x(y+2)Step 2: ∫(y+2)−1dy=∫xdxStep 3: ln∣y+2∣=2x2+C1Step 4: eln∣y+2∣=e2x2+C1Step 5: ∣y+2∣=e2x2eC1Step 6: y+2=Ce2x2Step 7: y=Ce2x2−2Is Lara's work correct? If not, what is her mistake?Choose 1 answer:(A) Lara's work is correct.(B) Step 1 is incorrect. We're not allowed to factor an expression when solving differential equations.(C) Step 2 is incorrect. The separation of variables wasn't done correctly.(D) Step 4 is incorrect. The right-hand side of the equation should be e2z2+C1.
Factor out x: Lara's initial equation is (dxdy=xy+2x). Step 1: She factors out x from the right-hand side to get (dxdy=x(y+2)).
Separate variables: Lara attempts to separate variables by writing ∫(y+2)−1dy=∫xdx.
Integrate both sides: She integrates both sides to get ln∣y+2∣=2x2+C1.
Exponentiate both sides: Lara exponentiates both sides to remove the natural logarithm, writing eln∣y+2∣=e(2x2)+C1.
Simplify expressions: She simplifies the left-hand side to ∣y+2∣ and the right-hand side to e(x2)/2eC1.
Find general constant: Lara writes y+2=Ce2x2, where C=eC1 is the general constant.
Solve for y: She solves for y to get y=Cex2/2−2.
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