Question

The point (-2, K) lies on the circle x^2 +y^2= 20. Find the values of k. Show all the steps

Answer 1

I will plug in the POINTS including k in the equation each point in its place either x or y.

`( - 2)^(2) +( {k})^(2) = 20 \\ 4 + {k}^(2) = 20 \\ k^(2) + 4 - 20 = 0 \\ {k}^(2) - 16 = 0 \\ (k + 4)(k - 4) = 0 \\ \\ k + 4 = 0 \\ \\ or \\ \\ k - 4 = 0 \\ \\ k = 4 \\ or \\ k = - 4`

ATTACHED IS THE SOLUTION