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Question
Find the value of 'k' so that the quadratic equation 3x2 – 5x – 2k = 0 has real and equal roots.
Solution
Given quadratic equation is 3x2 – 5x – 2k = 0
For real and equal roots D = 0; i.e., b2 – 4ac = 0
On comparing the given equation with ax2 + bx + c = 0, we get
a = 3, b = –5 and c = –2k
∴ b2 – 4ac = 0
⇒ (–5)2 – 4(3)(–2k) = 0
⇒ 25 + 24k = 0
⇒ k = `- 25/24`
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