00:01
Okay, this question is to us is to find the slope of the tangent line of this equation at x equals 0 .15 and then verify it using the derivative finding function on the calculator.
00:13
Okay, so we need to take the derivative.
00:15
Clearly, we're going to use quotient rule.
00:17
So y prime equals x the denominator times the derivative of the top.
00:22
The derivative of the top will be 6 cosine 3x, that 3 popping out in front, minus the derivative of the top.
00:31
The bottom which is 1 times the original top which is 2 sine 3x all over the denominator squared okay we don't have to worry about simplifying this down too much because we're substituting a number in here we're substituting in that 0 .15 .1 .5 times 3 will be 0 .45 make a little bit easier calculations okay we're substituting in 0 .15 oh sorry about that everywhere we see an x and we are dividing by 0 .15 squared.
01:11
Okay.
01:12
We'll use our calculator for this number crunching.
01:15
So set up a fraction.
01:21
0 .156 cosine.
01:34
0 .45.
01:40
Minus 2 sine 0 .45.
01:45
Divided by 0 .15 squared.
01:52
Gives us negative 2 .646...