Hi there:) so i have gotten this question in my homework, and its not that i dont understand how to find a tangent to a curve, i just dont understand this question!!!:(:( so here it is:(adsbygoogle = window.adsbygoogle || []).push({});

"The line x+y-k=0 is a tangent to the circle x^2+y^2-2x+4y-72=0. Find the value(s) of k.

Does this mean i am to solve the equation as a quadratic, and obtain the values of x to find the values of k?

I have tried to solve it as y=sqrt(-x^2+2x-4y+72),but the graph turned out totally different from the first one.

could anybody hely me? would really appreciate it!!!:)

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# Homework Help: Questions about finding values of a tangent

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