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Higher Maths- The Circle Watch

1. Can someone please help me? Find the values of k for which the line y=x+k is a tangent to the circle x^2+y^2=5.
I have substituted the line into the circle equation then tried doing the discriminant but it hasn't worked as the answer is k =−10 10 square rooted.
2. (Original post by sabrinaclark23)
Can someone please help me? Find the values of k for which the line y=x+k is a tangent to the circle x^2+y^2=5.
I have substituted the line into the circle equation then tried doing the discriminant but it hasn't worked as the answer is k =−10 10 square rooted.
Try again. You should get from the discriminant.

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