Superposition of counter-propagating waves with unequal amplitudes

Steps:

• Identify amplitudes: first wave has amplitude 4, second has amplitude A/2.
• For waves traveling in opposite directions, the maximum combined amplitude occurs during constructive interference: 4 + A/2.
• The minimum combined amplitude occurs during destructive interference: |4 - A/2|.
• The ratio is (4 + A/2) / |4 - A/2|, but A is undefined.

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Final answer: Not enough information.