Question

If a and b are the zeroes of this quadratic polynomial f (x)=x2-5x+4,find the value of 1/a +1/b- 2ab?

Answer 1

Answer:-17/4

Step-by-step explanation:

Answer 2

The value of $\bold{\frac{1}{a}+\frac{1}{b}-2 a b = \frac{-27}{4}}\end{array}\bold$

A "quadratic polynomial" has a degree 2 and it is also called as a univariant quadratic polynomial. The equation involving "quadratic polynomial" is called as a polynomial equation. A "closed form" of solution is called as quadratic formula.

$\begin{array}{l}{f(x)=x^{2}-5 x+4} \\ {f(x)=x^{2}-4 x-x+4}\end{array}$

f(x) = x(x-4)-1(x-4)  

f(x) =(x-1)(x-4)  

Hence a=1 and b=4

$\begin{array}{l}{\frac{1}{a}+\frac{1}{b}-2 a b=\frac{1}{1}+\frac{1}{4}-2(1)(4)} \\ \\ {=1+\frac{1}{4}-8} \\\\ {=\frac{4+1-32}{4}} \\\\ {\frac{1}{a}+\frac{1}{b}-2 a b=\frac{-27}{4}}\end{array}$