Question

Answer 1

a) \(\left(P\right):x-2y+2z+4=0\Rightarrow\overrightarrow{n_1}=\left(1;-2;2\right)\RightarrowĐúng\)

b) \(\overrightarrow{n_2}=-2\left(1;-2;2\right)=\left(-2;4;-4\right)\Rightarrow\overrightarrow{n_2}=-2\overrightarrow{n_1}\RightarrowĐúng\)

c) \(d\left(I;\left(P\right)\right)=\dfrac{\left|1-2.0+2.2+4\right|}{\sqrt{1^2+\left(-2\right)^2+2^2}}=\dfrac{9}{3}=3\Rightarrow Sai\)

d) \(\left(S\right):\left(x-1\right)^2+y^2+\left(z-2\right)^2=9\Rightarrow R=3;I\left(1;0;2\right)\)

Giả sử \(\left(S\right)\) tiếp xúc \(\left(P\right)\) tại \(I\Rightarrow d\left(I;\left(P\right)\right)=R=3\left(đúng\right)\)

\(\RightarrowĐúng\)