Question

If y= Acosx+ B sinx then prove that d²x/ dx²+ y =0​ please help soon

Answer 1

$y = Acosx + Bsinx \\ \frac{dy}{dx} = - Asinx + Bcosx \\ \frac{{d}^{2} y}{d {x}^{2} } = - Acosx - Bsinx \\ \\ now \: \: \: \frac{ {d}^{2}y }{d {x}^{2} } + y \\ = - Acosx - Bsinx + Acosx + Bsinx \\ = 0$

Answer 2

your answer dear hope you like it