Question

05.
If the equation 2ka? - 40x + 25 = 0 has equal roots then the value of k is
(A)8
(B) 16
(C) 32
(D) 4​

Answer 1

Answer:

⇒  The given quadratic equation is 2kx2−40x+25=0, comparing it with ax2+bx+c=0

⇒  We get, a=2k,b=−40 and c=25.

⇒  It is given that the roots are real and equal.

∴    b2−4ac=0

⇒  (−40)2−4(2k)(25)=0

⇒  1600−200k=0

⇒  200k=1600

⇒  k=8

⇒  Hence, the answer is 8

Answer 2

Answer:

Here is your answer,

PX) 2kx*-40x+25

If it has equal roots then Discriminate(D) =

D 0

b- 4ac=0

(-40)- 4*2k*25 = 0

1600 200k = 0

1600 200k

k 83

When k is equal to 8 i.e. 16x- 40x +25

has equal roots.