Question

Given that P(x)=2x²+5x-5

Answer 1

Answer:

$(i) P(\frac{1}{2}) = 2*(\frac{1}{2})^2 + 5*\frac{1}{2} -5$

          $=\frac{1}{2} +\frac{5}{2} -5\\\\=3-5 = -2$

$(ii) P(3) - Q(2) = 2(3^2)+5(3)-5 -[4(2^2) +3(2) +2]$

                       $= 18 + 15 -5 -16-6-2= 28-24 =4$

$(iii) P(x)\cdot Q(x) = (2x^2+5x-5)(4x^2-3x+2)$

                      $=2x^2(4x^-3x+2) +5x(4x^2-3x+2)-5(4x^2-3x+2)\\\\=8x^4 -14x^3 -11x^2 -10x-20x^2+15x-10\\\\=8x^4 - 14x^3 -31x^2 +5 -10$

$(iv) P(x) + Q(x) = 2x^2 +5x -5 + 4x^2 -3x +2$

                         $= 6x^2 +2x -3$