document.write( "Question 906001: How do you find a Polynomial that passes through the points (-2,-1) (-1,7) (2,-5), (3,-1)? \n" ); document.write( "
Algebra.Com's Answer #549586 by josgarithmetic(39620)\"\" \"About 
You can put this solution on YOUR website!
Infinitely many polynomials can contain those four points. Pick as low a degree function as you can.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "A root occurs between x at -2 and -1.
\n" ); document.write( "A root occurs between x at -1 and 2.
\n" ); document.write( "We do not expect a root between x at 2 and 3.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "The function f may be degree 3 with a positive leading coefficient. From -1 to 2, f decreases, and from 2 to 3, f increases.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"ax%5E3%2Bbx%5E2%2Bcx%2Bd=y\" can be the general form for the cubic equation, and specific equations can be made from each of the four given points. Setup a system of equations and solve for a, b, c, and d.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Simplify the equations; Solve the system any way you know.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "(Yes, those are FOUR different equations, but they are a SYSTEM OF EQUATION. They are linear in the variables, a, b, c, d. They are based on the a general form from the cubic equation which is still unknown, \"ax%5E3%2Bbx%5E2%2Bcx%2Bd=y\").
\n" ); document.write( "
\n" );