When I first walked in calculus class I was like "ahhh, help" and sadly I still am. I do understand how to do the product and quotient rule. I think I get the concept of everything, but I always seem to get stuck in the middle of each problem.
The only thing I'm fully confident in doing is finding the derivatives of -4x^3+2x^2-3x+1. For each term, you take the exponent and multiply it by the constant and subtract one from the exponent. Also, the derivative of any number is 0. for -4x^3: 3(-4)= -12 3-1=2 for 2x^2: 2(2)=4 2-1=1 for -3x: -3(1) = -1 1-1=0 So, then you have -12x^2+4x-3.
Also, I think I'm getting average speed, but can anyone tell me if I'm doing this right: Given the position equation s(t)=3t^2-3t-4, find the anverage velocity from t=2 to t=4. So, I ended up getting (2,4). I then plugged in 2 and then 4 to the equation 3t^2-3t-4. When I plugged in I got 2 and 32. After that I plugged (2,4) and 2, 32 in to the slope formula. For my final answer I got 15.
I think I'm having trouble more with the algebra kind of stuff. for example: [(-3x^2+5x-5)(sinx)] I understand copy the first, derivative of second, minus, copy the second, derivative of first (-3x^2+5x-5)(cosx)-(sinx)(-6x+5) but then what's the next step to solving?
Also, I don't understand problems like x(1-4/x+3) Do I use the product rule or no? I just don't know where to start for this one.
Yeah I'm kind of confused on a lot, but hopefully someone can help me before the test. (pleaseeeee haha)
Subscribe to:
Post Comments (Atom)
Looks great Abbey!
ReplyDeleteOk, I'm a little confused. when you said [(-3x^2+5x-5)(sinx)], why did you start doing the quotient rule, because I'm pretty sure you're multiplying that..(unless there was supposed to be a / in there somewhere, no biggie)? So, using the product rule would give you:
ReplyDelete(-3x^2 + 5x - 5)(cosx) + (sinx)(-6x + 5)
Then you distribute and combine like terms if any.
For x((1 - 4)/(x + 3)), what I did was just use the product rule, and when I took the derivative of the fraction part, I used the quotient rule (by the way, is it just 1-4 on top which is -3?).
So:
x(-3/(x+3)^2) + (-3/x+3)(1)
simplifies to:
(-3x)/((x+3)^2) + (-3)/(x+3)
and I think that's simplified.
**this is what I think is right..could be wrong, just sayin'**
I always think anything that is getting multiplied together to a group of terms is product rule material.
ReplyDeleteSo for the example you showed, you would need to use product rule.
for the x(1-4/x+3) what you do is you distribute the x after you distribute you could take the derivative and then you can use the quotient rule on the fraction side of the problem
ReplyDeleteMal thanks I meant to say the product rule I must be loosing my mind with all this calculus ha. Thanks it still helped!
ReplyDelete