document.write( "Question 281375: if f(x)=x^2+3x+4 find f(-1) \n" ); document.write( "

Algebra.Com's Answer #204411 by Mathematicians(84) $\"\"$ $\"About$

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The notation of f(-1) is a tricky one. Basically, you take the -1 and plug it in for all the x's.\r
\n" ); document.write( "\n" ); document.write( "For your example:\r
\n" ); document.write( "\n" ); document.write( " $\"f%28x%29=x%5E2%2B3x%2B4+\"$ \r
\n" ); document.write( "\n" ); document.write( "is really\r
\n" ); document.write( "\n" ); document.write( " $\"f%28-1%29+=+%28-1%29%5E2+%2B+3%28-1%29+%2B+4\"$ \r
\n" ); document.write( "\n" ); document.write( "When you square a negative, it is the same thing as multiplying a negative with a negative which turns into positive so:\r
\n" ); document.write( "\n" ); document.write( " $\"%28-1%29%5E2+%2B+3%28-1%29+%2B+4+=+1+-3+%2B+4+=+2\"$ \r
\n" ); document.write( "\n" ); document.write( "Basically $\"f%28-1%29+=+2\"$ \n" ); document.write( "

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