Verify that the function`y = a cos x + b sin x`, where, a, `b in R`is a solution of the differential equation `(d^2y)/(dx^2)+y=0`.

Explanation

To verify that the function \( y = a \cos x + b \sin x \) is a solution of the differential equation

\[ \frac{d^2y}{dx^2} + y = 0, \]

we will follow these steps:

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