document.write( "Question 1200622: A quadratic polynomial of the form y=x^2+bx+c has x-intercepts at x=-7 and x=-3. What is the y-intercept of this parabola?\r
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Algebra.Com's Answer #834794 by ikleyn(52781) $\"\"$ $\"About$

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\n" ); document.write( "A quadratic polynomial of the form y=x^2+bx+c has x-intercepts at x=-7 and x=-3.
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document.write( "y-intercept is the value of this quadratic polynomial at x= 0.\r\n" );
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document.write( "Substitute x= 0 into the polynomial, and you will see that y-intercept is the value\r\n" );
document.write( "of the coefficient \"c\".\r\n" );
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document.write( "According to Vieta's theorem, coefficient \"c\" (the constant term) is the product of the roots of the polynomial.\r\n" );
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document.write( "The roots are -7 and -3 (given), and their product is (-7)*(-3) = 21.\r\n" );
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document.write( "So, y-intercept is 21.    ANSWER\r\n" );
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