Register to reply 
Couple Simple Grade 12 Calculas Homework Help NEEDED 
Share this thread: 
#1
Apr412, 10:52 AM

P: 25

TO EVERYBODY, THIS IS NOT MY HOMEWORK. I HAVE A TEST TOM and these are some questions that I just dont know how to do, I gave attempts to some and some I am just missing something. Plus, these questions are from all over the unit so its not my homework. I need it done asap. So then I know how someone did it and I can understand that way as fast as possible. Thankyou. ALSO SOME OF THEM I MANAGED TO WRITE WHAT I GOT BUT SOME DERIVATIVES QUESTIONS WERE TOO COMPLICATED TO TYPE.
 1. Find the derivative of the following functions using the f(x+h)  f(x)/h a. ƒ(x) = 1/2x Show all your steps It did it but I am not getting the right answer. Just remember its not (1/2)x. It should be 1/(2x)  2. A rocket is fired into the air with an initial velocity of 98 m/s. The height ( h ) of the rocket after t seconds is given by the expression h = 98t  4.9t2. a. What the average rate of change for the first 2 seconds. Time Height 0 0 1 93.1 2 176.1 Average rate of change = 88.2 m I know the answer is 88.2. But can anyone please show me the steps thnx.  3. If you invest $5000 compounded continuously at 4% p.a. how much will this investment be worth in 5 years? you should use the formula A(t) = Pe^(rt)  4. A population of 500 E. coli bacteria doubles every 15 minutes. Use this information to find an expression for this population growth. Using this expression, find what the population would be in 87 minutes. Use an exponential model. In P(t) = 500 e^kt for minutes, then: 1000 = 500 e^15k 2 = e^15k 15k = ln2 k = (ln2)/15 Now, I am stuck. Now, can someone use the formula A(t) = Poe^(kt), and sub in what you know and sub in 87 for t to find A(t).  5. c. What is the equation for the derivative of y = (0.75)x? I GOT THIS y = 1.00000022063(0.75)x I have 1.000(0.75)^x as an answer, but the 1.000.... is incorrect.. CAN SOMEONE FIX IT.  6. Find the derivative of the following functions using the f(x+h)  f(x)/h Show all your steps a. ƒ(x) = x^2 + 5x b. ƒ(x)= 1/2^x 


#2
Apr412, 10:57 AM

Mentor
P: 18,040

Please provide attempts to ALL the questions, or this will be deleted.



#3
Apr412, 11:01 AM

P: 25




#4
Apr412, 11:03 AM

P: 25

Couple Simple Grade 12 Calculas Homework Help NEEDED
Can you just answer these please, I'll learn from the answers, these are these only six I am stuck on, if I get these, then I am good.



#5
Apr412, 11:06 AM

Mentor
P: 18,040

1 and 6. Plug in everything in (f(x+h)f(x))/h
2. What is the elevant formula for average rate of change? 3 and 4. What is P, r and t? 5. You have something of the form y=ax for a constant. What is the relevant formula? 


#7
Apr412, 11:09 AM

P: 25




#9
Apr412, 11:11 AM

P: 25

FOR # 4
P= 5000 i= .04/365 = .0001096 n=1025 5000 (1.0001096)^1025 = 5594.43 I asked my teacher too she said my answer is only like 500 away plus she told me to use the formula A(t) = Poe^(kt), and sub in what you know and sub in 87 for t to find A(t). 


#10
Apr412, 11:18 AM

Mentor
P: 18,040

Try it this way: After 0 minutes, there are 500 bacteria. After 15 minutes, there are 500*2 bacteria After 15*2 minutes, there are 500*2² bacteria ... How many bacteria are there after 15n minutes? 


#11
Apr412, 11:21 AM

P: 25

For #1, I dont know how to put in, this is what I did
1/2(x+h)  1/2(x)  h BUT ITS NOT (1/2)x. It should be 1/(2x).. and I dont know how to put in 1/(2x) 


#12
Apr412, 11:24 AM

Mentor
P: 18,040

So you have
[tex]\frac{\frac{1}{2(x+h)}\frac{1}{2x}}{h}[/tex] Try to add up the two fractions in the numerator. 


#13
Apr412, 11:35 AM

P: 25

I got to this point....
(1/2x) + (1/2h)  (1/2x) x (1/h) 


#14
Apr412, 11:36 AM

Mentor
P: 18,040

It is NOT true that 1/a + 1/b = 1/(a+b). Try to add up the fractions using the correct formula. Hows do you add up two fractions? 


#15
Apr412, 11:38 AM

P: 25

I am really confused.



#16
Apr412, 11:44 AM

P: 25

or you meant...
1/(2x+2h)1/2x ... wouldnt it be 1/2h left??? so we have 1/2h x 1/h.. we cross multiply, we get h/2h= 1/2 


#17
Apr412, 11:45 AM

Mentor
P: 18,040

No, that is incorrect.
You should review how to add up fractions. 


#18
Apr412, 04:07 PM

Sci Advisor
HW Helper
Thanks
P: 4,958

RGV 


Register to reply 
Related Discussions  
Calculas homework question  Calculus & Beyond Homework  2  
I'm New And I Have A Couple Questions For Grade 12 Physics...Please Help  Introductory Physics Homework  5  
Help needed on a couple questions  Introductory Physics Homework  1 