Natural Join and Select operation in Relational Algebra

CONSIDER A SCHEMA R(A,B) AND S(B,C) Q1 AND Q2 ARE QUERIES EXPRESSED IN RA   

  Q1=SIGMA(A=1) (R*S)   Q2=  ( SIGMA(A=1) R)  *S  HERE * DENOTES NATURAL JOIN  AND SIGMA MEANS SELECT OF RA

  does Q1 AND Q2 PRODUCE SAME RESULTS OR Q1 CONTAINS THE RESULTS OF Q2. THANK YOU.

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