Question

The value of p for which the equation 8x^2 + 9px + 15 has equal roots is \(\frac {4\sqrt {30}}{9}\).

(a) True

(b) False

I had been asked this question by my school teacher while I was bunking the class.

Query is from Quadratic Equation topic in chapter Quadratic Equation of Mathematics – Class 10

Answer 1

The correct option is (a) True

The best explanation: Roots are equal.  ∴ b^2 – 4ac = 0

(9p)^2 – 4(8)(15) = 0

81p^2 – 480 = 0

81p^2 = 480

p = ± \(\sqrt {\frac {480}{81}}\) = ± \(\frac {4\sqrt {30}}{9}\)