#### notes

1. Both are operations on functions.

2. Both satisfy the property of linearity, i.e.,

i) `d/(dx)[k_1f_1 (x) + k_2 f_2 (x)] = k_1 d/(dx) f_1(x) + k_2 d/(dx) f_2(x)`

ii) `int [k_1 f_1 (x)+k_2 f_2 (x)] dx = k_1 int f_1 (x) dx +k_2 int f_2 (x) dx `

Here `k_1` and `k_2` are constants.

3. We have already seen that all functions are not differentiable. Similarly, all functions are not integrable. We will learn more about nondifferentiable functions and nonintegrable functions in higher classes.

4. The derivative of a function, when it exists, is a unique function. The integral of a function is not so. However, they are unique upto an additive constant, i.e., any two integrals of a function differ by a constant.

5. When a polynomial function P is differentiated, the result is a polynomial whose degree is 1 less than the degree of P. When a polynomial function P is integrated, the result is a polynomial whose degree is 1 more than that of P.

6. We can speak of the derivative at a point. We never speak of the integral at a point, we speak of the integral of a function over an interval on which the integral.

7. The derivative of a function has a geometrical meaning, namely, the slope of the tangent to the corresponding curve at a point. Similarly, the indefinite integral of a function represents geometrically, a family of curves placed parallel to each other having parallel tangents at the points of intersection of the curves of the family with the lines orthogonal (perpendicular) to the axis representing the variable of integration.

8. The derivative is used for finding some physical quantities like the velocity of a moving particle, when the distance traversed at any time t is known. Similarly, the integral is used in calculating the distance traversed when the velocity at time t is known.

9. Differentiation is a process involving limits.

10. The process of differentiation and integration are inverses of each other.