The format of the calculation problem is:

Prototype =XXXX Type II XXX=XXXX

=XXX X=XX

Prove the problem:

Proof: ∫XXXX

∴XX (∵ because. Because. You can write more More than once. You can write more)

∵XXX

∴XXX (∵ This is because. This is because. You can write more More than once. You can write more)