# Classify the following as linear, quadratic and cubic polynomials:

i) x^{2} + x ii) x - x^{3 }iii) y + y^{2} + 4 iv) 1 + x v) 3t

vi) r^{2 }vii) 7x^{3}

**Solution:**

Let's understand the meaning of a linear, quadratic and cubic polynomial.

A polynomial of degree one is called a linear polynomial represented as ax + b.

A polynomial of degree two is called a quadratic polynomial represented as ax^{2} + bx + c.

A polynomial of degree three is called a cubic polynomial represented as ax^{3} + bx^{2} + cx + d.

i) x^{2} + x → Quadratic polynomial since the degree is 2.

ii) x - x^{3 }→ Cubic polynomial since the degree is 3.

iii) y + y^{2} + 4 → Quadratic polynomial since the degree is 2.

iv) 1 + x → Linear polynomial since the degree is 1.

v) 3t → Liner polynomial since the degree is 1.

vi) r^{2} → Quadratic polynomial since the degree is 2.

vii) 7x^{3} → Cubic polynomial since the degree is 3.

**Video Solution:**

## Classify the following as linear, quadratic and cubic polynomials: (i) x² + x (ii) x - x³ (iii) y + y² + 4 (iv) 1 + x (v) 3t (vi) r² (vii) 7x³

### NCERT Solutions Class 9 Maths - Chapter 2 Exercise 2.1 Question 5:

**Summary:**

Thus, we see that, 1 + x, 3t are linear polynomials, x^{2} + x, y + y^{2} + 4, r^{2} are quadratic polynomials, and x - x^{3}, 7x^{3 }are cubic polynomials.