Question

<br />If -3 is the root of quadratic equation 2x^2 + px - 15 = 0, while the quadratic<br />equation x^2 - 4px + k = 0 has equal roots. Find the value of k' please dont spam .......I WILL MARK AS BRAINLIST​

Answer 1

Given

p(x) = 2x² + px - 15

x = -3 {root of the polynomial p(x)}

putting (-3) in the polynomial p(x)

=> 2(-3)² + p(-3) - 15 = 0

=>2 × 9 - 3p - 15 = 0

=> 18 - 3p - 15 = 0

=> -3p + 3 = 0

=> -3p = -3

=> p = -3/-3

=> p = 1

Now, put the value of 'p' in the given equation

=> x² - 4px + k

=> x² - 4(1)x + k

=> x² - 4x + k

Comparing with the form ax² + bx + c

a = 1 {coefficient of x²}

b = -4 {coefficient of x}

c = k {constant term}

For equal roots, discriminant (D) = 0

=> b² - 4ac = 0

=> (-4)² - 4(1)(k) = 0

=> 16 - 4k = 0

=> 4k = 16

=> k = 16/4

=> k = 4

The value of 'k' is 4

Answer 2

the value of the k =4......