find the value of k for which the give equation has real and equal root :(k+1) x²-2(k-1)x+1=0
Answers
Answer:
The value of k is 3
Given:
(k+1)x×2-2(k-1)x+1=0(k+1)x×2−2(k−1)x+1=0
To find:
The value of k
Solution:
We know that,
For a quadratic equation x^{2}+b x+c=0x
2
+bx+c=0 , if the roots are real and equal then
Discriminant b^{2}-4ac=0 \rightarrow(1)b
2
−4ac=0→(1)
Now, in an equation (k+1) x \text { times } 2-2(k-1) x+1=0(k+1)x times 2−2(k−1)x+1=0
a = k+1, b= -2(k-1), c=1a=k+1,b=−2(k−1),c=1
Given that roots are real and equal
Therefore,
[-2(k-1)]^{2}-4(k+1)(1]=0[−2(k−1)]
2
−4(k+1)(1]=0
Now, the above equation can be written as,
4\left(k^{2}-2 k+1\right)-4 k-4=04(k
2
−2k+1)−4k−4=0
On simplifying the above equation, we get
4\left(k^{2}-2 k+1\right)-4 k-4=04(k
2
−2k+1)−4k−4=0
Now, +4 and -4 get cancelled,
\begin{gathered}\begin{array}{c}{4 k^{2}-12 k=0} \\\\ {4 k^{2}=12 k} \\\\ {k=3}\end{array}\end{gathered}
4k
2
−12k=0
4k
2
=12k
k=3
Explanation:
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Explanation:
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