let f be a function defined by f(x)=4-x^2 when x=<1 and k+x when x>1(adsbygoogle = window.adsbygoogle || []).push({});

What value of k will f be continuous at x=1?

I know the answer is k=2, however, I dont know how to show to correct work. I got 2 when I sketched a graph of 4-x^2 and plugged in some numbers but I dont know how to show it algebraically/using an actual method.

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# Homework Help: Showing continuity

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