document.write( "Question 1121043: If f(7)=-5, g(7)=2, f'(7)=3, and g'(7)=-1, find (2f.3g)'(7). Show your calculation. \n" ); document.write( "

Algebra.Com's Answer #737051 by ikleyn(52832) $\"\"$ $\"About$

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\n" ); document.write( "If f(7) = -5, g(7) = 2, f'(7) = 3, and g'(7) = -1, find (2f.3g)'(7). Show your calculation.
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document.write( "The correct solution is  THIS:\r\n" );
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document.write( "(2f.3g)'(7) = 2f'(7)*3g(7) + 2f(7)*3g'(7) = (2*3)*(3*2) + (2*(-5))*(3*(-1)) = 66.\r\n" );
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document.write( "It uses standard formula for derivative of a product\r\n" );
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document.write( "(u*v)' = u'*v + u*v'.\r\n" );
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\n" ); document.write( "\n" ); document.write( "The tutor @greenestamps misread the problem and inadvertently gave incorrect solution.
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