Question

In the quadratic equation px2-2√5px+15=0 has two equal roots then. Find the value of P

Answer 1

For equal roots

b^2 - 4ac= 0

So,

10p^2 - 60p = 0

10p^2 = 60p

p^2/p = 60/10

p= 6

Answer 2

Since, the equation has equal roots. Therfore, it's discriminant(D) is 0.

Now, D is b^2 - 4ac

So, b^2 - 4ac is 0

i.e. (-2√5p)^2 - 60p is 0

Hence, 20p^2 - 60p is 0

20p(p-3) is 0

We get, 20p is 0 OR p-3 is 0

Finally, p is 0 or p is 3.

But p can't be 0 because if it's 0 then the equation no longer remains quadratic.

So, p is 3.

Hope this helps...