M4maths Previous Puzzles

18 Jun 2013 Quadratic Equation

If one root of a quadratic equation 3x^2+px+4=0 is 2/3. Find the other root of the equation.

OPtion

1) -8
2) 6
3) 5
4) -4
5) 4
6) 3
7) 2
8) 1
9) 8
10) None of these

Solution

One root is 2/3
3(2/3)^2+p(2/3)+4=0
solve, p=-8
Equation is
3x^2-8x+4=0
solve
x=2/3,x=2
other root x=2
option 7

Correct Option: 7 Best Solution (0)