## Multiplication with modulus of function

Hi!
whether |Cos(theta)|*Cos(theta) = Cos^(theta) , because it means that only positive values of Cos(theta) are taken.
Am I right?

 = Cos^2(theta)

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 Quote by Silva_physics Hi! Could anybody, please, tell me: whether |Cos(theta)|*Cos(theta) = Cos^(theta) , because it means that only positive values of Cos(theta) are taken. Am I right?
That's not a well phrased question. |Cos(theta)| is necessarily positive but the "Cos(theta)" outside the "modulus" is not so resticted.

In general |a|*a is equal to $a^2$ if a is non-negative, but equal to $-a^2$ if a is negative.

Thanks