document.write( "Question 176268: If f(x)=4-3x, find f^(-1)(-41) \n" ); document.write( "

Algebra.Com's Answer #131456 by EMStelley(208) $\"\"$ $\"About$

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First, you need to find the inverse function for f. This is done by first replacing f(x) with y,
\n" ); document.write( " $\"y=4-3x\"$
\n" ); document.write( "Next, you swap the two variables.
\n" ); document.write( " $\"x=4-3y\"$
\n" ); document.write( "And lastly, you solve for y so that it is in y= format again.
\n" ); document.write( " $\"x-4=-3y\"$
\n" ); document.write( " $\"y=%28-1%2F3%29x%2B4%2F3\"$
\n" ); document.write( "This is the inverse function:
\n" ); document.write( " $\"f%5E-1x=%28-1%2F3%29x%2B4%2F3\"$
\n" ); document.write( "So if we want to evaluate the inverse function at -41, we just plug in -41 for x now and obtain that
\n" ); document.write( "f^(-1)(-41)=(-1/3)(-41)+4/3=(41/3)+4/3=45/3=15 \n" ); document.write( "

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