Saved Bookmarks
| 1. |
Question numbers 27 TO 34 luniIf - 1 is a zero of the polynomial 2x3 - x? - 5x - 2,find its other zeroes.of work in 5 |
|
Answer» The other zeroes are 2 and -1/2.... -1 is one zeroesso x= -1x+1=0 is a factor2x^3-x^2-5x-22x^3+2x^2-3x^2-3x-2x-22x^2(x+1)-3x(x+1)-2(x+1)(x+1)(2x^2-3x-2)= polynomial2x^2-3x-2=02x^2-4x+x-2=02x(x-2)+1(x-2)=0(x-2)(2x+1)=0either x-2=0, x=22x+1=0, x= -1/22, -1/2& -1 are the zeroes -1 is zeroesso x+1 is a factor of 2x^3-x^2-5x-2x+1)2x^3-x^2-5x-2(2x^2-3x-2 2x^3+2x^2 -. --------------------------- -3x^2-5x-2 -3x^2-3x +. + ------------------- -2x-2 -2x-2 +. + ------------+(x+1)(2x^2-3x-2)= 2x^3-x^2-5x-22x^2-3x-2=02x^2-4x+x-2=02x(x-2)+1(x-2)=0(x-2)(2x+1)=0x-2=0, x=22x+1=0, 2x= -1, x= -1/22, -1,2 & -1 are the zeroes |
|