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Let y(x) be a function satisfying (d^(2)...

Let `y(x)` be a function satisfying `(d^(2)y)/(dx^(2))-(dy)/(dx)+e^(2x)=0`, y(0)= and `y^(')(0)=1`. If maximum value of `y(x)` is `y(alpha)`, then integral part of `2alpha` is……………..

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To solve the differential equation given in the problem, we will follow these steps: ### Step 1: Write the differential equation The differential equation is given as: \[ \frac{d^2y}{dx^2} - \frac{dy}{dx} + e^{2x} = 0 \] ### Step 2: Substitute \( t = \frac{dy}{dx} \) Let \( t = \frac{dy}{dx} \). Then, we have: \[ \frac{d^2y}{dx^2} = \frac{dt}{dx} \] Substituting this into the equation gives: \[ \frac{dt}{dx} - t + e^{2x} = 0 \] ### Step 3: Rearranging the equation Rearranging the equation, we get: \[ \frac{dt}{dx} = t - e^{2x} \] ### Step 4: Finding the integrating factor The integrating factor \( \mu(x) \) for the equation \( \frac{dt}{dx} - t = -e^{2x} \) is: \[ \mu(x) = e^{-\int 1 \, dx} = e^{-x} \] ### Step 5: Multiply through by the integrating factor Multiplying the entire equation by \( e^{-x} \): \[ e^{-x} \frac{dt}{dx} - e^{-x} t = -e^{x} \] ### Step 6: Integrate both sides The left side can be written as: \[ \frac{d}{dx}(t e^{-x}) = -e^{x} \] Integrating both sides gives: \[ t e^{-x} = -e^{x} + C \] where \( C \) is the constant of integration. ### Step 7: Solve for \( t \) Thus, \[ t = -e^{2x} + Ce^{x} \] ### Step 8: Use initial conditions to find \( C \) From the problem, we know \( y'(0) = 1 \): \[ t(0) = -e^{0} + C e^{0} = 1 \implies -1 + C = 1 \implies C = 2 \] So, \[ t = -e^{2x} + 2e^{x} \] ### Step 9: Integrate \( t \) to find \( y \) Now, we integrate \( t \) to find \( y \): \[ \frac{dy}{dx} = -e^{2x} + 2e^{x} \] Integrating gives: \[ y = -\frac{1}{2} e^{2x} + 2e^{x} + D \] Using the initial condition \( y(0) = 2 \): \[ y(0) = -\frac{1}{2} e^{0} + 2e^{0} + D = 2 \implies -\frac{1}{2} + 2 + D = 2 \implies D = \frac{1}{2} \] Thus, the function \( y \) is: \[ y = -\frac{1}{2} e^{2x} + 2e^{x} + \frac{1}{2} \] ### Step 10: Find the maximum value of \( y \) To find the maximum, we set \( \frac{dy}{dx} = 0 \): \[ -e^{2\alpha} + 2e^{\alpha} = 0 \implies e^{\alpha}(2 - e^{\alpha}) = 0 \] This gives \( e^{\alpha} = 2 \) or \( \alpha = \ln(2) \). ### Step 11: Calculate \( 2\alpha \) Thus, \[ 2\alpha = 2\ln(2) = \ln(4) \] ### Step 12: Find the integral part of \( 2\alpha \) The integral part of \( \ln(4) \) is: \[ \lfloor \ln(4) \rfloor \] Since \( \ln(4) \) is greater than 1 but less than 2, we have: \[ \lfloor \ln(4) \rfloor = 1 \] ### Final Answer The integral part of \( 2\alpha \) is: \[ \boxed{1} \]
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