Question

The value of f(x)=5x+4x^2+3whenx=-1 is:

Answer 1

Answer:

f(x) = 5x+4x²+3

f(-1) = 5×(-1) + 4×(-1)² + 3

= -5+4+3

=-5+7

=2

The value is 2.

Answer 2

Answer:

The value of f(x) = 5x + 4x² + 3 at x = -1 is 2.

Step-by-step explanation:

Given

• f(x) = 5x + 4x² + 3

To Find

Value of f(x) at :-

• x = - 1

Solution :

$\: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \sf \implies \: f( \green{x}) = 5 \green{x} + {4 \green{x}}^{2} + 3$

$\: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \sf \implies \: f( \green{ - 1}) = 5 \green{( - 1)} + {4 \green{( - 1)}}^{2} + 3$

$\: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \sf \implies \: f( \green{x}) = - 5 + {4} + 3$

$\: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \sf \implies \: f( \green{x}) = - 5 + 4 + 3$

$\: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \sf \implies \: f( \green{x}) = 2$

What is Remainder theorem ?

• Remainder theorem just says that if a polynomial p(x) is divided by the polynomial x - a then the remainder will be p(a).

• Dividend = (Divisor × Quotient) + Remainder [ That's what a remainder theorem is.]

Here , p(x) is a dividend .

and (x - a) = divisor.

Ploughing remainder theorem :

p(x) = (x-a)·q(x) + r

p(a) = (a-a)·q(a) + r

p(a) = (0)·q(a) + r

p(a) = r

Yes , p(a) is remainder ! and that's why it's known as remainder theorem.

• Polynomial : A variable bases language in maths. or A string of variables and numbers put together.

• Degree of polynomial : Highest power of a polynomial is called degree of polynomial.

• Coefficient : A number by which a variable is multiplied.

• Constant : It's a numerical term holding no variable.