Q. dtdy=2y, and y=8 when t=0.Solve the equation.Choose 1 answer:(A) y=e8t(B) y=e2t(C) y=8e2t(D) y=2e8t
Recognize Linear Homogeneous Differential Equation: Recognize that the given differential equation is a first-order linear homogeneous differential equation which can be solved using separation of variables.
Separate and Integrate Variables: Separate the variables by dividing both sides by y and multiplying both sides by dt to get ydy=2dt.
Solve for Constant C: Integrate both sides of the equation. The integral of y1 dy is ln∣y∣, and the integral of 2 dt is 2t. So, ∫(y1)dy=∫2dt leads to ln∣y∣=2t+C, where C is the constant of integration.
Calculate Value of C: Solve for the constant C using the initial condition y=8 when t=0. Plugging in the values, we get extln∣8∣=2imes0+C, which simplifies to extln(8)=C.
Substitute C into Equation: Calculate the value of C using the natural logarithm of 8.C=ln(8)=ln(23)=3ln(2).
Exponentiate to Solve for y: Substitute the value of C back into the equation ln∣y∣=2t+C to get ln∣y∣=2t+3ln(2).
Simplify Exponential Expression: Exponentiate both sides to solve for y. We get ∣y∣=e2t+3ln(2).
Drop Absolute Value for Final Solution: Simplify the right side using properties of exponents. e3ln(2) is the same as (eln(2))3, which simplifies to 23 or 8. So, ∣y∣=e2t×8.
Drop Absolute Value for Final Solution: Simplify the right side using properties of exponents. e3ln(2) is the same as (eln(2))3, which simplifies to 23 or 8. So, ∣y∣=e2t×8. Since y is positive for t=0 and y=8, we can drop the absolute value to get y=8e2t.