- #1
Rib5
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I was doing a signals and systems problem and I think I might be screwing something up with the cosine function because I get
[tex]cos(a+b) = cos(a)*cos(b)[/tex]
This is how
[tex]cos(a+b)=Re\left\{ e^{j*(a+b)} \right\}[/tex]
[tex]=Re\left\{ e^{j*(a)}*e^{j*(b)} \right\}[/tex]
[tex]=cos(a)*cos(b)[/tex]
Can anyone point out my mistake?
EDIT:
I guess I figured it out. The Re{} function isn't distributive. Thanks for your time.
[tex]cos(a+b) = cos(a)*cos(b)[/tex]
This is how
[tex]cos(a+b)=Re\left\{ e^{j*(a+b)} \right\}[/tex]
[tex]=Re\left\{ e^{j*(a)}*e^{j*(b)} \right\}[/tex]
[tex]=cos(a)*cos(b)[/tex]
Can anyone point out my mistake?
EDIT:
I guess I figured it out. The Re{} function isn't distributive. Thanks for your time.