I'm supposed to use a graphing calculator to find the limit of (x^2)/(cos(5x) - cos(4x)) as x approaches 0 but nothing shows up when I hit the graph button on my TI 84 plus. Anyone know what's wrong?

Question

anonymous · Answer

make sure your calculator is in radian mode

anonymous · Answer

and also make sure your domain is set properly. if you are taking the limit as x goes to zero you might try -.2 to .2

anonymous · Answer

looks like zero in wolfram lets see http://www.wolframalpha.com/input/?i=%28x%5E2%29%2F%28cos%285x%29+-+cos%284x%29%29+

anonymous · Answer

no it is not zero http://www.wolframalpha.com/input/?i=limit+as+x+goes+to+0%28x%5E2%29%2F%28cos%285x%29+-+cos%284x%29%29+

anonymous · Answer

Switching to radian mode solved the problem. Thanks!