# Numerical Integration

#### khánh huy

##### New member
I don't understand why they can have an equation (7) with the integration at the right-hand side?

#### Romsek

##### Full Member
somehow I don't think this belongs in the beginning algebra forum.

#### MarkFL

##### Super Moderator
Staff member

I don't understand why they can have an equation (7) with the integration at the right-hand side?View attachment 13585
Suppose we have:

$$\displaystyle I=\int_a^b k_1t^2+k_2t+k_3\,dt$$

Then, using (7), we may state:

$$\displaystyle I=k_1(A_0t_0^2+A_1t_1^2+A_2t_2^2)+k_2(A_0t_0+A_1t_1+A_2t_2)+k_3(A_0+A_1+A_2)$$

Do you see now why integration is required as part of the definition of (7)?

#### khánh huy

##### New member
somehow I don't think this belongs in the beginning algebra forum.
This is in my linear algebra so i think it belongs to algebra and a little calculus

#### khánh huy

##### New member

Suppose we have:

$$\displaystyle I=\int_a^b k_1t^2+k_2t+k_3\,dt$$

Then, using (7), we may state:

$$\displaystyle I=k_1(A_0t_0^2+A_1t_1^2+A_2t_2^2)+k_2(A_0t_0+A_1t_1+A_2t_2)+k_3(A_0+A_1+A_2)$$

Do you see now why integration is required as part of the definition of (7)?
I know what you mean but i still don't know how to have the equation(7)
Thank you very much Mr. MarkFL!!