For any two vectors `veca` and `vecb`, prove that : `|veca+vecb|le|veca|+|vecb|`. Also, write the name of this inequality

For any two vectors veca and vecb , prove that |veca.vecb|le|veca||vecb| Also write the name of this inequality.

For any two vectors vecaandvecb , prove that |veca+vecb|le|veca|+|vecb| . Also write the name of this inequality.

Prove that |veca|-|vecb| le|veca - vecb | .

For two non-zero vectors veca and vecb , write when |veca+vecb|=|veca|+|vecb| holds.

If veca*vecb=-|veca|*|vecb| , then theta= ,

If veca*vecb=-|veca||vecb| , then theta=

This ineqality |veca.vecb|le|veca||vecb| is called

If veca=-vecb , is it true that |veca|=|vecb| ?

If two vectors veca and vecb are such that : |veca|=2,|vecb|=1 and veca*vecb=1 , then find the value of (3veca-5vecb)*(2veca+7vecb) .