I have two simple questions but I'm not 100% on how to get the correct result.(adsbygoogle = window.adsbygoogle || []).push({});

1. "The noise is reduced by 6 dB" means its amplitude is cut to _%?

How is it calculated to 50%? I try 20log(Av)...

2. Does this wave contain 30k hertz sine function? (see attachment)

The answer is yes, but I try f=1/T, in this case T = 0.1 ms, so f is 10k, how is it 30k?

Thank you

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# Noise reduction and square wave/sine function question

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