Gonna bug you with some more math--sorry

Pre-College Topics High School Life
1

<p>1) On a calculator, is typing in 1-cos squared of 3x (1-cos^2)3x the same as 1-(cos 3x)^2 because I can't get the squared to go before the parenthese on my calculator. </p>

<p>2) Is there a number a such that the limit x--> 3</p>

<p>(2x^2-3ax+x-a-1)/(x^2-2x-3) exists? My friend told me you just have to guess and check and that's the only way. Anyone know how to go about this one?</p>

2

<p>1) the input should look like the latter: 1-(cos3x)^2.
2) just plug in 3 to the equation, but that yields an undefined number (b/c the denominator sums to 0). so, you should factor the top and then simplify and then plug in 3.</p>