Recent content by jackchen

Do you know how I can solve this? or where I can find a good explanation? Thank you! =)

I'm afraid I don't. I'm very weak in Calculus, sorry!

Homework Statement I'm stuck halfway in my differentiation. The question is: Suppose f(x) is the following function when x > 0, find the x-coordinate of the critical point of f(x). Homework Equations Equation = f(x) = e^x - 5x^2 - ln(x) The Attempt at a Solution I solved for...

Another question: Find the enclosed area between the curves, with the equations: y = x^2 - 14x y = 5.8x - x^2 My working Using the rule: x = - (b/2a) f(x) = x^2 - 14x x = - (-14/2(1)) = 7 f(x) = 7^2 - 14(7) = -49 Minimum turning point = (7, -49) g(x) = 5.8x - x^2 x = -(5.8/2(-1)) =...

Hello Dr Dick, the question is: "When a = 191, there is more than one critical point. Considering the x-coordinates of the critical points, what is the value of the greatest x-coordinate, giving your answer to 2 decimal places?" Will my answer be correct now? Sorry I'm very weak in Calculus.

Hello, I'm sorry, it should be (7x + 8) ^ 0.75 / (7(0.75)) I wrote wrongly, I'm sorry!

I have another question 3. Question: f(x) = x^4 + ax^2 When "a" = 191, there is more than 1 critical path. Considering the x-coordinates of the critical path, find the greatest value of x to 2 decimal places. My working: ==> f(x) = x^4 + (191)x^2 ==> f'(x) = 4x^3 - (382)x = 0 ==>...

Hello, for question 1, this is what I've worked out. Original Question: 1 / (7x + 8)^0.25 dx (upper=33, lower=18) This becomes: ==> (7x + 8) ^ -0.25 dx ==> ((7x + 8) ^ 0.75) / ( 7 ^ 0.75) ==> 4/21 [(7x + 8) ^ 0.75] Replacing x with upper limit of 33, and lower limit 18 ==> 4/21...

Thank you gb7nash! I've worked out the following for question 2: "(x^1.6 + 26) / x" will become "(x^1.6 / 1.6) + 26ln(x)" Replacing x with the upper and lower limits: ((33^1.6 / 1.6) + 26ln(33)) - ((5^1.6 / 1.6) + 26ln(5)) I get: 258.9838875 - 50.05328511 = 208.9306018 Is this...

Hello, please pardon me as I'm very weak in Math and Calculus. For Question 2: If it becomes x^0.6 + 26/x, according to my textbook "26/x" will become "26ln(x)"? x^0.6 is supposed to be f'(x) right? Am I supposed to convert it back to f(x)? How do I do that with the power being 0.6...

Hello! For 1) I don't know u-substitution. For 2), what do you mean by dividing the terms by x? I replaced the equation once with 33 (upper limit for x), and another time with 5 (lower limit for x), then substract them together. What is the correct way? Thanks! =)

For Question 1: : [ln|(7x+8)^0.25|] (upper=33, lower=18) Replace x with upper and lower, and subtract, I've got 3.931872942 - 3.402328159 = 0.529544783 For Question 2: : (33^1.6 + 26) / 33 - (5^1.6 + 26) / 5 = 8.936954709 - 7.826527804 = 1.110426905 Am I right? Thanks! =)

I'm a new Calculus student, and it's killing me! Please help! :( Thank you Homework Statement Find to 2-decimal place of the following integrals. Homework Equations 1. (Upper limit= 33, lower limit= 18) 1 / ([7x+8]^0.25) dx 2. (Upper limit = 33, lower limit = 5) (x^1.6 + 26)...

Now, we all know from our own telescopes and stuff, we manage to capture images (light) from stars 1000 light years away from us. Thus what we capture is what the stars look like 1000 years ago. They could look different now. So, assuming at this instance, I have a telescope-camera placed...