Question

AD is tangent to circle O at D. Find AB. Round to the nearest tenth if necessary. Thank you.

Answer 1

Answer:

AB=2.1

Step-by-step explanation:

we know that

Applying the Intersecting Secant-Tangent Theorem

$(BC+AB)(AB)=AD^{2}$

substitute the given values and solve for AB

$(15+AB)(AB)=6^{2}$

Let

x=AB

substitute

$(15+x)(x)=36$

$x^{2}+15x-36=0$

Solve the quadratic equation by graphing

The solution is x=2.1

see the attached figure

therefore

AB=2.1