Question

Is one of the zeros of the quadratic polynomial f into x is equal to 4 x square - 80 x minus 9 is equal in magnitude but opposite in sign of the other then find the value of k?

Answer 1

Hey there!
Your question seems to be having some problems with its transcription.
The correct question is as follows :

If one of the zeroes of the quadratic polynomial f(x) = 4x² - 80kx - 9 is equal with the other but opposite in sign of the other, find the value of k.


Now,
Let ø be one of the roots, By the question, ø is other roots.

Sum of roots = ø - ø= 0 .

Also , We know that For a quadratic equation with its coefficients a, b, c respectively in decreasing order of the degree.

Then, Sum of roots = -b/a = -80k/4

Also,
We have -80k/4 = 0

-80k = 0
k = 0 .

Therefore, k = 0 .

Answer 2

heya first of all ur question is incomplete
acc. to given condition let root be € and -€
but for an answer we can assume the equation as
4x^2-80kx -9 = 0
on comparing above eqn with general eqn
ax^2+bx +c = 0
a= 4, b = -80k
c = -9
since sum of roots = -b/a = 80k/4 = €-€ = 0
thus k= 0