Write the given expression as a single trigonometric function.sin(42°)cos(17°) – cos(42°)sin(17°)

Use the sine difference identity: sin(A − B) = sin A cos B − cos A sin B. With A = 42° and B = 17°, the expression becomes sin(42° − 17°) = sin(25°). The matching choice is sin(25°).

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