Question

The quadratic equation whose roots are 1 and -1/2 is * A)2x^2+x-1=0 B)2x^2-x-1=0 C)2x^2+x+1=0 D) 2x^2-x+1=0

Answer 1

Answer:

Sum of roots = -1/2 + 1 = 1/2

Product of roots = -1/2 * 1 = - 1/2

Quadratic equation are written in form of x^2 - Sx + P = 0, where S is the sum of roots and P is the product of roots, here,

equation is -

= > x^2 - (1/2)x + (-1/2) = 0

= > ( 2x^2 - x - 1 )/2 = 0

= > 2x^2 - x - 1 = 0

Verifying-

= > 2x^2 - x - 1 = 0

= > 2x^2 - 2x + x - 1 = 0

= > 2x( x - 1 ) + ( x - 1 ) = 0

= > ( x - 1 )( 2x + 1 ) = 0

= > ( x - 1 ) = 0 or ( 2x + 1 ) = 0

= > x = 1 or x = -1/2

Hence the required equation is 1 or - 1/2.

Answer 2

Answer:

2x^2-x-1=0

Step-by-step explanation:

I hope it helps u