Question

If 2 is a root of the quadratic equation 3x2 + px – 8 = 0 and the quadratic equation 4x2 – 2px + k=0 has equal roots,find the value of k.​

Answer 1

Answer:

3x²+px-8=0

3(2)²+p(2)-8=0

3*4+2p - 8=0

2p+12-8=0

2p=-4

p=-2

4x²-2px+k=0

comparing it with ax²+bx+c=0

we get a= 4. b=-2p. c=k

A/q :: b²-4ac=0. (as equation has real roots)

(-2p)²- 4* 4 * k=0

(-2*-2)² -16k=0;. (p= -2)

16-16k=0

16k=16

k=1