Mathematical interpolation is "linear interpolation". The principle is that if A (I 1, B 1) and B (I 2, B2) are two points, then the point P(i, b) is on the straight line determined by the above two points. In engineering, I is between I 1 and I2, so P is between point A and point B, so it is called "linear interpolation method".

Mathematical interpolation shows that the variables reflected by point P follow the linear relationship reflected by straight line AB.

The above formula is easy to get. A, B, P three-point * * * line, and then

(b-b1)/(I-I1) = (B2-b1)/(I2-I1) = the slope of a straight line, and the result can be obtained through transformation.

Interpolation is widely used in financial management, such as calculating the time value of money, finding interest rate I and number of years n; In bond valuation, yield to maturity who seeks bonds; In the project investment decision-making index, seek the internal rate of return.