Masago is my best friend.

Masahide is my best friend.

Mr. Masagaki is my best friend.

Mr. Takeshige is my best friend.

I will start working as a regular employee from next month.

A positive number is a number greater than zero.

This problem requires the calculation of the tangent.

This 正數 is the same as what I learned in school.

Calculating the value of secant, one of the trigonometric functions, is difficult.

The calculation of versine is a part of trigonometry.