Which constant should be added and substracted to solve the quadratic equation 4x^2 – √3x – 5 = 0
Which constant should be added and substracted to solve the quadratic equation 4x2 – √3x – 5 = 0 by the method of completing the square?
A) 3/16
B) √3/4
C) 9/16
D) 3/4
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Correct option is (A) 3/16
Given equation is \(4x^2-\sqrt{3}x-5=0\)
\(\Rightarrow(2x)^2-2\times2x\times\frac{\sqrt{3}}4-5=0\) \((\because2\times2x\times\frac{\sqrt{3}}4=\sqrt3x)\)
\(\Rightarrow(2x)^2-2\times2x\times\frac{\sqrt3}4\) \(+(\frac{\sqrt3}4)^2-5-(\frac{\sqrt3}4)^2=0\)
\(\Rightarrow(2x-\frac{\sqrt3}4)^2-(5+\frac3{16})=0\)
Thus, we have to add or subtract \(\frac{3}{16}\) to solve the given quadratic equation by the method of completing the square.
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