Q41 of 82 Page 4

If the equation has equal roots, prove that .(CBSE 2017)

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


D = b2 – 4ac


If D = 0, roots are equal



⇒ D = 4m2c2 – 4(c2 – a2)(1 + m2) = 0


⇒ m2c2 – c2 + a2 – c2m2 + a2m2 = 0


⇒ c2 = a2(1 + m2)

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