Question

Explain the distance formula then use it to calculate the distance between A(1, 1)and B(7, -7)

Answer 1

The Distance Formula = $\sqrt{( X_{2} - X_{1}) ^{2}+( Y_{2} - Y_{1}) ^{2}}$
A(1,1) ⇒ the first 1 is $X_{1}$ & the second 1 is $Y_{1}$ .
B(7,-7) ⇒ the first 7 is $X_{2}$ & the second is -7 is $Y_{2}$ .
Now all you have to do is SUBSTITUTE the variables into the distance formula to get: $\sqrt{(7-1) ^{2}+(-7-1) ^{2}}$ .
After you plug that formula into your graphing calculator (or solve it manually & mentally), you should end up with the answer 10, therefore d=10.