Question

Salah satu persamaan garis singgung lingkaran x²+y²=10 melalui titik (2,4) adalah...

Answer 1

y-4=m(x-2)

y-4-mx+2m=0

|0-m*0-4+2m|/√(1+m²)=√10

(2m-4)²/(1+m²)=10.

(2m-4)²=10(1+m²)

4m²-16m+16=10+10m²

10+10m²-( 4m²-16m+16)=0

6m²+16m-6=0

3m²+8m-3=0

(m+3)(3m-1)

m1=⅓ m2=-3

y-4=m(x-2); m=⅓

y-⅓x-4+2/3=0

y-⅓x-10/3=0

y-4=m(x-2); m=-3

y-4+3x-6=0;

y+3x-10=0;