Advertisements
Advertisements
प्रश्न
Find the zeroes of the quadratic polynomial `f(x) = 5x^2 ˗ 4 ˗ 8x` and verify the relationship between the zeroes and coefficients of the given polynomial.
Advertisements
उत्तर
We have:
`f(x) = 5x^2 ˗ 4 ˗ 8x`
`= 5x^2 ˗ 8x ˗ 4`
`= 5x^2 ˗ (10x ˗ 2x) ˗ 4`
`= 5x^2 ˗ 10x + 2x ˗ 4`
`= 5x (x ˗ 2) + 2(x ˗ 2)`
`= (5x + 2) (x ˗ 2)`
∴ f(x) = 0 ⇒ (5x + 2) (x ˗ 2) = 0
⇒ 5x + 2= 0 or x ˗ 2 = 0
`⇒ x = (−2)/5 or x = 2 `
So, the zeroes of f(x) are `((−2)/5)` and 2
Sum of zeroes =`((-2)/5)+2=(-2+10)/5=8/5="(-Coefficient of x)"/(("Coefficient of" x^2))`
Product of zeroes=`((-2)/5)xx2=(-4)/5= "Constant term"/(("Coefficient of" x^2))`
APPEARS IN
संबंधित प्रश्न
The graphs of y = p(x) are given in following figure, for some polynomials p(x). Find the number of zeroes of p(x).

Find the zeroes of the polynomial `f(x) = x^2 ˗ 2x ˗ 8` and verify the relation between its zeroes and coefficients
Obtain all other zeroes of `(x^4 + 4x^3 – 2x^2 – 20x – 15)` if two of its zeroes are `sqrt5 and –sqrt5.`
Find all the zeroes of polynomial `(2x^4 – 11x^3 + 7x^2 + 13x – 7)`, it being given that two of its zeroes are `(3 + sqrt2) and (3 – sqrt2)`.
Find ∝ , β are the zeros of polynomial ∝ +β= 6 and ∝β 4 then write the polynomial.
If -4 is a zero of the polynomial `x^2 – x – (2k + 2) is –4`, then find the value of k.
If the sum of the zeros of the quadratic polynomial `kx^2-3x + 5` is 1 write the value of k..
If ∝ and β are the zeros of the polynomial f(x) = `6x^2 + x - 2 `find the value of `(∝/β+∝/β) `
If the zeroes of the polynomial `f(x) = x^3 – 3x^2 + x + 1` are (a – b), a and (a + b), find the values of a and b.
If the zeroes of the quadratic polynomial x2 + (a + 1) x + b are 2 and –3, then ______.
The number of polynomials having zeroes as -2 and 5 is ______.
10. The zeroes of the quadratic polynomial x² + kx + k, k? 0.
If one of the zeroes of a quadratic polynomial of the form x² + ax + b is the negative of the other, then it ______.
If x3 + 11 is divided by x2 – 3, then the possible degree of remainder is ______.
The number of polynomials having zeroes as -2 and 5 is ______.
If the graph of a polynomial intersects the x-axis at exactly two points, it need not be a quadratic polynomial.
Which of the following is not the graph of a quadratic polynomial?
The number of quadratic polynomials having zeroes –5 and –3 is ______.
The graph of y = f(x) is shown in the figure for some polynomial f(x). The number of zeroes of f(x) are ______.

