gaokao 2020 Q10

gaokao · China · national-III-science 5 marks Tangents, normals and gradients Common tangent line to two curves

If line $l$ is tangent to both the curve $y = \sqrt { x }$ and the circle $x ^ { 2 } + y ^ { 2 } = \frac { 1 } { 5 }$ , then the equation of $l$ is
A. $y = 2 x + 1$
B. $y = 2 x + \frac { 1 } { 2 }$
C. $y = \frac { 1 } { 2 } x + 1$
D. $y = \frac { 1 } { 2 } x + \frac { 1 } { 2 }$

If line $l$ is tangent to both the curve $y = \sqrt { x }$ and the circle $x ^ { 2 } + y ^ { 2 } = \frac { 1 } { 5 }$ , then the equation of $l$ is

A. $y = 2 x + 1$

B. $y = 2 x + \frac { 1 } { 2 }$

C. $y = \frac { 1 } { 2 } x + 1$

D. $y = \frac { 1 } { 2 } x + \frac { 1 } { 2 }$

Paper Questions

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