Q. Find the particular solution, y=f(x), to the differential equation dxdy=ycosx given f(23π)=−1
Separate and Integrate: Step 1: Separate variables and integrate.We start by separating the variables in the differential equation dxdy=ycosx. Rearrange to get ydy=cosxdx. Now, integrate both sides:∫ydy=∫cosxdx21y2=sinx+C
Solve for y: Step 2: Solve for y.To find y, we take the square root of both sides:y=±2(sinx+C)
Find C with Initial Condition: Step 3: Use the initial condition to find C. We know that f(23π)=−1. Plugging x=23π into y=±2(sinx+C): −1=±2(sin(23π)+C) Since sin(23π)=−1, −1=±2(−1+C) Squaring both sides gives: 1=2(−1+C)1=−2+2CC0C1
Write Particular Solution: Step 4: Write the particular solution.With C=23, the solution becomes:y=±2(sinx+23)Since we need the solution that passes through (23π,−1) and we calculated earlier:−1=−2(sin(23π)+23)The correct sign is negative, so:y=−2(sinx+23)
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