表达式11: left parenthesis, "X" , "Y" left brace, "R" cos left parenthesis, "R" times "T" Subscript, "h" "e" "t" "a" , Baseline , right parenthesis greater than or equal to 2 , right brace , right parenthesisX,YRcosR·Theta≥2
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表达式12: "R" equals StartRoot, "X" squared plus "Y" squared , EndRootR=X2+Y2
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表达式13: "T" Subscript, "h" "e" "t" "a" , Baseline equals arc tangent left parenthesis, "Y" , "X" , right parenthesisTheta=arctanY,X
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This graphs!
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表达式15: "r" Subscript, 0 , Baseline cosine left parenthesis, "r" Subscript, 0 , Baseline times theta Subscript, 0 , Baseline , right parenthesis greater than or equal to 2r0cosr0·θ0≥2
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表达式16: "r" Subscript, 0 , Baseline equals StartRoot, "x" squared plus "y" squared , EndRootr0=x2+y2
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表达式17: theta Subscript, 0 , Baseline equals arc tangent left parenthesis, "y" , "x" , right parenthesisθ0=arctany,x
