A circle has center at –6 + 2i and a point on the circle at 4 + 26i. Which of the following points is also on the circle? 
–19 + 15i
–16 – 22i
6 + 16i
20 – 24i

Respuesta :

it would be option 2

Answer:

 Option B (-16-22i)                                                

Step-by-step explanation:

Given : A circle has a center -6+2i and a point is 4+26i

To find : which point is also on the circle

Solution : First we find the radius(r) of the circle with center(x,y)=(-6,2)

and a point (h,k)=(4,26)

Equation of the circle = [tex](x-h)^2+(y-k)^2=r^2[/tex]

where, [tex]r=\sqrt{(x-h)^2+(y-k)^2}[/tex]

[tex]r=\sqrt{(4-(-6))^2+(26-2)^2}[/tex]

[tex]r=\sqrt{(10)^2+(24)^2}[/tex]

[tex]r=\sqrt{100+576}[/tex]

[tex]r=\sqrt{676}[/tex]

[tex]r=26[/tex]

Now we check one by one that which point satisfy the equation

New equation : [tex](x+6)^2+(y-4)^2=676[/tex]

A) point –19 + 15i  = (-9,15)

[tex](-19+6)^2+(15-2)^2=676[/tex]

[tex](-13)^2+(13)^2=676[/tex]

[tex](169)+(169)=676[/tex]

[tex]338\neq676[/tex]

B) –16 – 22i  =(-16,-22)

[tex](-16+6)^2+(-22-2)^2=676[/tex]

[tex](-10)^2+(-24)^2=676[/tex]

[tex](100)+(576)=676[/tex]

[tex]676=676[/tex]

C) 6 + 16i  =(6,16)

[tex](6+6)^2+(16-2)^2=676[/tex]

[tex](12)^2+(14)^2=676[/tex]

[tex](144)+(196)=676[/tex]

[tex]340\neq676[/tex]

D) 20 – 24i=(20,-24)

[tex](20+6)^2+(-24-2)^2=676[/tex]

[tex](26)^2+(-26)^2=676[/tex]

[tex](676)+(676)=676[/tex]

[tex]1352\neq676[/tex]

Therefore, Option B only satisfy the required equation

Hence, Option B (-16-22i) is the answer.