In class we started operation with radicals

how would you answer a question like this

determine the length of the line segment from A(-2,7), to B (4,1)?

sqrt [ ( x 2 - x 1 ) ^ 2 + ( y 2 - y 1 ) ^ 2 ]

L = sqrt [ ( 4 - ( - 2 ) ) ^ 2 + ( 1 - 7 ) ^ 2 ]

L = sqrt [ ( 4 + 2 ) ^ 2 + ( 1 - 7 ) ^ 2 ]

L = sqrt [ 6 ^ 2 + ( - 6) ^ 2 ]

L = sqrt ( 36 + 36 )

L = sqrt ( 72 )

L = sqrt ( 4 * 9 * 2 )

( Remark : sqrt ( 4 ) = 2 ; sqrt ( 9 ) = 3 )

L = 2 * 3 * sqrt ( 2 )

L = 6 sqrt ( 2 )