Question

pt is a tangent and pAB is a secent if pt = 6cm and AB=5cm <br />then find the length of PA <br />this question is very important for board exam class 10 plz solve the question

Answer 1

By tangent secant property

➡PA×PB=PT^2

➡PA×(PA+AB)=36

➡PA×(PA+5)=36

➡PA^2+5PA-36=0

➡PA^2+9PA-4PA-36=0

➡PA(PA+9)-4(PA+9)=0

➡(PA-4)(PA+9)

Either PA=4 or PA=-9

But PA can't be negative as it is a side therefore we discard PA=-9

Hence,PA=4CM