Q15 of 82 Page 4

For what value of k does the quadratic equation

px(x – 3) + 9 = 0 have equal roots? (CBSE 2014)

 


For a quadratic equation, ax2 + bx + c = 0,


D = b2 – 4ac


If D = 0, roots are real and equal



⇒ px2 – 3px + 9 = 0


⇒ D = 9p2 – 4 × 9 × p = 0


⇒ p = 4

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