Q. Find the equation of the curve for which y′′=x34 and which is tangent to the line 2x+y=5 at the point (1,3).
Integrate to find derivative: Integrate the second derivative to find the first derivative.Given y′′=x34, we integrate to find y′.∫(x34)dx=∫4x−3dxy′=−2x−2+C1We need to find the constant C1.
Find constant C1: Use the point of tangency to find the first constant C1. The curve is tangent to the line 2x+y=5 at the point (1,3). This means that the derivative of the curve at x=1 should be equal to the derivative of the line at that point. The derivative of the line 2x+y=5 is −2 (since dxdy=−2 when we differentiate 2x+y=5 with respect to x). So, C10 should equal C11. C12C13
Integrate for original function: Integrate the first derivative to find the original function y. Now that we have y′=−2x−2, we integrate to find y. ∫(−2x−2)dx=∫−2x−2dxy=2x−1+C2 We need to find the constant C2.
Find constant C2: Use the point of tangency to find the second constant C2. The curve passes through the point (1,3), so we can use this to find C2. y(1)=3 should equal 2(1)−1+C2. 3=2+C2C2=1
Write final curve equation: Write the final equation of the curve.Now that we have both constants, we can write the equation of the curve.y=2x−1+1Or, in a more conventional form:y=x2+1
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