Dividing P(x) by x+2
Then P(-2)= (-2)^2 +5(-2)+6
= 4-10+6
= 10-10
P(-2) = 0
∴ x+2 is a factor of x^2 +5x+6
- Solution of a quadratic equation by formula
Any quadratic equation of the form ax^2 +bx+c=0 can be solved by using the formula,
2 a
x=−b±^ b^2 −^4 ac
Solving of any quadratic equation will lead to two values which satisfy the given
equation, and these two values are called the roots of the equation.
First of all, the formula needs to be memorized. The idea may be taught orally supported
by relevant text material in Braille. Adequate practice must be given in enabling the
child to familiarize with the formula and knowing its components.
- Nature of roots
The two roots of an equation can be real and equal, real and unequal or imaginary.
It is not necessary to solve an equation to find the nature of its roots. The nature of
the roots can be judged by finding value of^ Δ=b^2 –4ac, which is called the
discriminant.
- Discriminant
Discriminant is a value which reveals about the nature of the roots of a quadratic
equation. Discriminant is denoted by the symbol Δ^ and its value is b^2 – 4ac. Note
that if,
