Please help I need help fast thanks sirs

asked Feb 10 in Calculus Answers by Rainer

These and similar questions have been recently answered, so you would learn more from studying the solutions given and so gain the understanding to tackle the problems yourself. You will get more of a kick from being able to solve them yourself than just having someone else work out the answers for you. When you do understand the methods you will have successfully prepared yourself for the concepts of calculus. If you are having difficulties understanding then leave a comment against the solutions and I or someone else will try to help you understand.

Best wishes

Your answer

Your name to display (optional):
Privacy: Your email address will only be used for sending these notifications.
Anti-spam verification:
To avoid this verification in future, please log in or register.

1 Answer

7. If h is the variation in length then 3(x+h)=30±0.06.

3x+3h=30±0.06, x+h=10±0.02. When x=10 h=±0.02, so the length of each piece must be within 0.02 in of 10 in.

8. Let x=3+h then (3+h)²=9±1. 9+6h+h²=9±1 so h²+6h±1=0 and h=(-6±√36±4)/2=-3±2√2 or -3±√10.

If we calculate all possible values for h we get -0.1716, -5.8284, 0.1623, -6.1623. Remember that x is close to 3 so we can reject the large negative values. That leaves -0.1716 and 0.1623 making x=(2.8284,3.1623).

Now we can see that x=3 is approximately in the middle of this interval. If we ignore the h² term in the quadratic because it is small compared to 3 we get 6h=±1 and h=±⅙=±0.17 making x=(2.83,3.17). So there is justification in ignoring the h² term. We can say that the values of x that guarantee f(x) to be within 1 unit of 9 are that x is in the interval (2.8,3.2).

For 0.2 units h=±0.2/6=±0.033 so x=(2.967,3.033). This is ⅕ of the value of h above and 0.2 is ⅕ of one unit.

The remaining questions have been answered elsewhere.

answered Feb 12 by Rod Top Rated User (592,720 points)

Related questions

1 answer
1 answer
1 answer
Welcome to, where students, teachers and math enthusiasts can ask and answer any math question. Get help and answers to any math problem including algebra, trigonometry, geometry, calculus, trigonometry, fractions, solving expression, simplifying expressions and more. Get answers to math questions. Help is always 100% free!
81,852 questions
86,192 answers
69,805 users