Given:
A figure of a circle. [tex]KJ=6,KL=x-2,ML=4[/tex].
To find:
The length of KJ.
Solution:
From the given figure it is clear that the number 6 is marked between K and J it means the number 6 represents the distance between the points K and j.
Therefore, the length of KJ is 6 units.
Note: In the given question we need to find KL instead of KJ because KJ is already given.
According to the tangent secant theorem:
[tex]a^2=bc[/tex]
Where,
Using the tangent secant theorem, we get
[tex]ML^2=KL\times JL[/tex]
[tex](4)^2=(x-2)\times (6+x-2)[/tex]
[tex]16=(x-2)\times (4+x)[/tex]
[tex]16=4x+x^2-8-2x[/tex]
On further simplification, we get
[tex]16=x^2+2x-8[/tex]
[tex]0=x^2+2x-8-16[/tex]
[tex]0=x^2+2x-24[/tex]
Splitting the middle term, we get
[tex]x^2+6x-4x-24=0[/tex]
[tex]x(x+6)-4(x+6)=0[/tex]
[tex](x+6)(x-4)=0[/tex]
[tex]x=-6,4[/tex]
For [tex]x=-6[/tex],
[tex]KJ=-6-2[/tex]
[tex]KJ=-8[/tex], which is not possible because side cannot be negative.
For [tex]x=4[/tex],
[tex]KJ=4-2[/tex]
[tex]KJ=2[/tex]
Therefore, the measure of KL is 2 units.
