In the adjacent figure, AP and BP are two tangents. Find their length if AP = 2x^2 + 6 and BP = 2x + 10.
The tangents will be equal in length, so: AP = BP ---> 2x2 + 6 = 2x + 10
Solving: 2x2 - 2x - 4 = 0 ---> x2 - x - 2 = 0 ---> (x - 2)(x + 1) = 0
So, either x = 2 or x = -1
If x = 2 ---> AP = 2·22 + 6 = 14 and BP = 2·2 + 10 = 14
If x = -1 ---> AP = 2·(-)2 + 6 = 8 and BP = 2·(-1) + 10 = 8