Q.

The quadratic equation whose roots are twice the roots of  2x2-5x+2=0 is

1 8x2-10x+2=0  
2 x2-5x+4=0  
3 2x2-5x+2=0  
4 x2-10x+6=0  

Ans.

(2)

Quadratic equation is 2x2-5x+2=0

Let α and β are its roots.

∴  α+β=52,  αβ=1

Now roots of another equation are α'=2α and β'=2β

     α'+β'=2α+2β=2(α+β)=5

      α'β'=2α×2β=4αβ=4

Now quadratic equation with roots α' and β' is

     x2-(α'+β')x+α'β'=0⇒x2-5x+4=0