document.write( "Question 117426: 1.) What is a polynomial function in standard form of degree 4 with zeros: -1, 2, 5i?\r
\n" ); document.write( "\n" ); document.write( "2.) Given f(x)=5x+1
\n" ); document.write( " Find f^-1(x) & verify the answer is correct by showing that (fof^-1)(x)=x\r
\n" ); document.write( "\n" ); document.write( "3.) solve: a) log (x+4) - log 2x=0
\n" ); document.write( "b) 2ln x + 5 = 7\r
\n" ); document.write( "\n" ); document.write( "4.) Find all the zeros of the polynomial function: P(x)=2x^4+3x^3+16x^2+27x-18 then write the P(x) as a product of its linear factors.\r
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Algebra.Com's Answer #85432 by psbhowmick(878)\"\" \"About 
You can put this solution on YOUR website!
1.) For any polynomial equation with real coefficients, complex roots occur in conjugate pairs.
\n" ); document.write( "So, if 5i i.e. (0 + 5i) is a root then (0 - 5i) is the other root.
\n" ); document.write( "Hence, the 4 zeros are x = -1, 2, 5i, - 5i
\n" ); document.write( "Hence the polynomial is
\n" ); document.write( "\"%28x+-+%28-1%29%29%28x+-+2%29%28x+-+5i%29%28x+-+%28-5i%29%29\"
\n" ); document.write( "= \"%28x+%2B+1%29%28x+-+2%29%28x+-+5i%29%28x+%2B5i%29\"
\n" ); document.write( "= \"%28x+%2B+1%29%28x+-+2%29%28x%5E2+-+25i%5E2%29\"
\n" ); document.write( "= \"%28x+%2B+1%29%28x+-+2%29%28x%5E2+%2B+25%29\"
\n" ); document.write( "= \"%28x%5E2+-+x+-+2%29%28x%5E2+%2B+25%29\"
\n" ); document.write( "= \"x%5E4+-+x%5E3+%2B+23x%5E2+-+25x+-+50\"\r
\n" ); document.write( "\n" ); document.write( "2.)
\n" ); document.write( "f(x) = 5x + 1
\n" ); document.write( "5x = f(x) - 1
\n" ); document.write( "\"x+=+%28f%28x%29-1%29%2F5\"
\n" ); document.write( "Hence, \"f%5E%28-1%29%28x%29+=+%28x+-+1%29%2F5\"\r
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\n" ); document.write( "\n" ); document.write( "Verification:
\n" ); document.write( "\"f%28f%5E%28-1%29%28x%29%29+=+5f%5E%28-1%29%28x%29+%2B+1+=+5%28x-1%29%2F5+%2B+1+=+x\"\r
\n" ); document.write( "\n" ); document.write( "3.a) \"log%2810%2Cx%2B4%29+-+log+%2810%2C2x%29+=+0\"
\n" ); document.write( "\"log%2810%2C%28x%2B4%29%2F2x%29+=+0\"
\n" ); document.write( "\"%28x%2B4%29%2F2x+=+1\"
\n" ); document.write( "\"%28x%2B4%29+=+2x\"
\n" ); document.write( "\"x+=+4\"\r
\n" ); document.write( "\n" ); document.write( "3.b) \"2log%28e%2Cx%29+%2B+5+=+7\"
\n" ); document.write( "\"2log%28e%2Cx%29+=+7+-+5+=+2\"
\n" ); document.write( "\"log%28e%2Cx%29+=+1\"
\n" ); document.write( "\"x+=+e\"\r
\n" ); document.write( "\n" ); document.write( "4.) Try yourself!
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