Math (Calculus)


I have a difficulty with the following question. The question is asking to find the slope of the tangent at x=3 for this function: f(x)=4x^3/sinx. X is measured in radians.

The is the derivative of f(x):

f'(x)=(12x^2)(sinx)^-1 + (4x^3)(-1)(sinx)^-2(cosx)

When x=3 is plugged in:

=f'(3)=(12(3)^2)(1/sin3) - 4(3)^3((cos3)/(sin3)^2)
=108(1/0.1411) - 108(-0.9900/(0.1411)^2)=6135.8

What I don't understand is why sin3 equals to 0.1411 and why cos3 is -0.9900.

I would be very grateful for your help.


  1. 👍
  2. 👎
  3. 👁
  1. since 3 radians is in QII, sin is positive, and cos is negative. 3 is almost pi: 171.9 degrees

    1. 👍
    2. 👎
  2. Hi Steve, thank you for the reply. I think I got it.

    1. 👍
    2. 👎

Respond to this Question

First Name

Your Response

Similar Questions

  1. Algebra

    Which quadratic equation has roots -1+4i and -1-4i ? A. x^2+2x+2=0 B. 2x^2+x+17=0 C. x^2+2x+17=0 D. 2x^2+x+2=0 I'm having difficulty with this question, but I've settled on C for now. Am I correct?

  2. L.A

    Which option describes a research question? A. a question that reveals where you can find information about a topic B. a question that encourages the reader to find out more about the topic C. a question placed in the conclusion

  3. math

    Original Question is: how many 1/2 miles are in 12 miles? write the division question 12 divided by 1/2= 24 what multiplication question could the model also answer? 12 x 2 =24 This is the one I didn't understand Write the

  4. Physics

    I'm understanding most of this physics, but here is one last question I would appreciate help on. Thank you! Okay, so the question involves a figure. A link to the question and the picture with it is below can be found by googling

  1. Career

    QUESTION 1 -It is important to upgrade your skills as the career world is in a constant state of change. *True False QUESTION 2 -An important component of career planning is completing career research. *True False QUESTION 3 -When

  2. Algebra

    Question 1 Solve using the multiplication principle then graph. -15>-75 Question 2 Translate to an equality. Use the variable x. The number of people in the chess clubi less than or equal to 15. Question 3 Solve using the addition

  3. Math

    Which of the following are categorical data? A.numbers of inches of rain B.types of drinks C.lengths of movies (in minutes) D.weights of students Which best describes a statistical question? A.a question that contains numbers B.a

  4. Math

    I need help with these three math question. 1st question. What is the additive inverse of 5 on the 12-hour clock? 2nd question. What is the equivalent number on the 12-hour clock. -22 the choices for this question is, 5 or 2 or 3

  1. english

    Which of the following would be the best approach to answering an essay question? Select one: a. Type the question into Google and use websites on the first page of results as the basis of your answer. b. Search the library

  2. English

    In the following example, what type of constructed response question is being used? In the story of the three little pigs, what material did the third little pig use to buy his house? Application – ‘Think and Search

  3. Math

    Need help with one more question. Which best describes a statistical question? a. a question that contains numbers b. a question about numbers c. a question about designing an experiment d. a question about a population or sample.

  4. Science

    What is the average summer temperature in the desert biome? Select one: a. 38 degrees celcius b. 48 degrees celcius c. 58 degrees celcius Question 2 Not yet answered Marked out of 1.00 Flag question Question text What is the

You can view more similar questions or ask a new question.