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Differential EquationsSuperchallengeThe Wronskian & Variation of Parameters

The Wronskian & Variation of Parameters · Superchallenge problem

Let qq be continuous on [0,∞)[0,\infty) and let yy solve y′′+q(t)y=0y''+q(t)y=0 with y(0)=1y(0)=1, y′(0)=0y'(0)=0. Suppose y(t)>0y(t)>0 for all t≥0t\ge0 and ∫0∞dty(t)2=3\displaystyle\int_0^\infty\dfrac{dt}{y(t)^2}=3. There is exactly one solution uu of the same equation with u(0)=1u(0)=1 and lim⁡t→∞u(t)y(t)=0\displaystyle\lim_{t\to\infty}\dfrac{u(t)}{y(t)}=0. Find u′(0)u'(0).