T can be used as a common letter in the method of substitution, which is actually the same as abcdefg, except that people often use T to answer some questions.

In case of moving point motion or other time problems, t can be set as unknown to solve. When learning functions, you can use t for convenient substitution operation. For example, let you ask for (x+ 1)? +2(x+ 1)- 10=0, and the direct operation is so complicated that x+1= t.

The original type became: t? +2t- 10=0, and then calculate the value of x according to x+ 1=t after calculating the value of t.

There are many such applications, in the final analysis, for the convenience of calculation and simplification ~

The answer is not easy. Thank you for your adoption ~