How i solve this ncert class 10th solution, of quadratic equation of exercise 4.4. I don’t know how to solve this question Find the values of k for each of the following quadratic equations, so that they have two equal roots.(ii) kx (x – 2) + 6 = 0
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Find the values of k for each of the following quadratic equations, so that they have two equal roots.(ii) kx (x – 2) + 6 = 0 Q.2(2)
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kx(x – 2) + 6 = 0
or kx2 – 2kx + 6 = 0
Comparing the given equation with ax2 + bx + c = 0, we get
a = k, b = – 2k and c = 6
We know, Discriminant = b2 – 4ac
= ( – 2k)2 – 4 (k) (6)
= 4k2 – 24k
For equal roots, we know,
b2 – 4ac = 0
4k2 – 24k = 0
4k (k – 6) = 0
Either 4k = 0 or k = 6 = 0
k = 0 or k = 6
However, if k = 0, then the equation will not have the terms ‘x2‘ and ‘x‘.
Therefore, if this equation has two equal roots, k should be 6 only.