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The equation
5x^(2) -2x+(2k-1)=0 has equal roots. Find the value of K

User TheFrack
by
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1 Answer

3 votes

Answer:

k = 3/5

Explanation:

You want the value of k that makes 5x² -2x +(2k-1) = 0 have equal roots.

Equal roots

The roots of the quadratic ax²+bx+c=0 will be equal when the discriminant d=b²-4ac is zero. Here, we have a=5, b=-2, c=(2k-1) and the discriminant is ...

d = b² -4ac = (-2)² -4(5)(2k-1)

d = 4 -20(2k-1) = 4 -40k +20 = 24 -40k

We want this to be zero, so ...

0 = 24 -40k

0 = 3/5 -k . . . . . . divide by 40, reduce the fraction

k = 3/5

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Additional comment

The attached graph shows the quadratic is tangent to the x-axis for k=3/5, meaning the roots are equal. They are x = 0.2.

The equation 5x^(2) -2x+(2k-1)=0 has equal roots. Find the value of K-example-1
User Thebat
by
5.9k points