The roots of the equation 4x3 + 16x2 - 9x - 36 = 0 given that sum of two - Maths - Complex Numbers and Quadratic Equations

Question

The roots of the equation 4x​3 + 16x2 -
9x - 36 = 0 given that sum of two of its roots is zero are ?

3 , -3 , -1
-4 , 3/2 , -3/2
4 , 3/2 , -3/2
1 , -1 , -9

Mayank Jha · Accepted Answer

Dear student,

The given equation can be re-written as:

4x3 + 16x2 - 9x - 36 = 0 ⇒4x2x + 4 - 9x + 4 = 0⇒x + 4 4x2 - 9 = 0 ⇒x + 42x + 32x - 3 = 0⇒x = -4; x = -32; x = 32Question also says that sum of two of its roots are zero and that is true for the values of x we got as:-32+32 = 0

Hence, the correct answer for this question is option (2)

The roots of the equation 4x​3 + 16x2 - 9x - 36 = 0 given that sum of two of its roots is zero are ? 3 , -3 , -1 -4 , 3/2 , -3/2 4 , 3/2 , -3/2 1 , -1 , -9

The roots of the equation 4x³ + 16x² - 9x - 36 = 0 given that sum of two of its roots is zero are ?

3 , -3 , -1

-4 , 3/2 , -3/2

4 , 3/2 , -3/2

1 , -1 , -9