Introduction to Linear Polynomials | Exercise 2.1

Question 1

Find the degrees of the following polynomials:

(i) 2x25x+32x^2 - 5x + 3

(ii) y3+2y1y^3 + 2y - 1

(iii) 9-9

(iv) 4z34z - 3

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Solution

The degree of a polynomial is the highest power of its variable.

Step 1 — Degree of 2x25x+32x^2 - 5x + 3

Let's look at the polynomial 2x25x+32x^2 - 5x + 3. The variable here is xx. We find the power of xx in each term. The powers of xx are 2, 1, and 0.

The highest power of xx is: Highest power=2\text{Highest power} = 2

Degree=2\boxed{\text{Degree} = 2}

Diagram 1

Step 2 — Degree of y3+2y1y^3 + 2y - 1

Now consider the polynomial y3+2y1y^3 + 2y - 1. The variable in this polynomial is yy. Let's check the power of yy in each term. The powers of yy are 3, 1, and 0.

The highest power of yy is: Highest power=3\text{Highest power} = 3

Degree=3\boxed{\text{Degree} = 3}

Step 3 — Degree of 9-9

Next, we have the polynomial 9-9. This is a constant polynomial. A constant polynomial has no variable term with a power greater than zero. We can write 9-9 as 9x0-9x^0.

The highest power of the variable is: Highest power=0\text{Highest power} = 0

Degree=0\boxed{\text{Degree} = 0}

Step 4 — Degree of 4z34z - 3

Finally, let's find the degree of 4z34z - 3. The variable in this polynomial is zz. We look at the power of zz in each term. The powers of zz are 1 and 0.

The highest power of zz is: Highest power=1\text{Highest power} = 1

Degree=1\boxed{\text{Degree} = 1}

Answer

(i) The degree of 2x25x+32x^2 - 5x + 3 is 2. (ii) The degree of y3+2y1y^3 + 2y - 1 is 3. (iii) The degree of 9-9 is 0. (iv) The degree of 4z34z - 3 is 1.

More questions in Exercise 2.1

Q1

Find the degrees of the following polynomials:

(i) 2x25x+32x^2 - 5x + 3

(ii) y3+2y1y^3 + 2y - 1

(iii) 9-9

(iv) 4z34z - 3

Q2

Write polynomials of degrees 1, 2 and 3.

Q3

What are the coefficients of x2x^2 and x3x^3 in the polynomial x43x3+6x22x+7x^4 - 3x^3 + 6x^2 - 2x + 7?

Q4

What is the coefficient of zz in the polynomial 4z3+5z2114z^3 + 5z^2 - 11?

Q5

What is the constant term of the polynomial 9x3+5x28x109x^3 + 5x^2 - 8x - 10?

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