Recent content by cinematic

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    High School Calculating speeds of radio to a planet

    Hi! I need help with the method to approach a question, if I wish to calculate how long it will take for a radio message to reach a certain planet (just the general concept), what will be the key pieces of information I require? I know I need: the distance from Earth to said planet the...
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    Trigonometric derivative: power rule + product rule

    Homework Statement Derive the following: y = (cosxsin2x)-2 2. The attempt at a solution Basically I saw this as a power rule with two products in the middle. So y = -2 (cos2cos2x-sinxsin2x)-1 But the correct answer is completely different, it's: 4(3sin2x - 1) all over...
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    Differentiating logarithmic functions

    Ok I finished the entire problem and got the right answer, thanks for the confirmation that my derivative was right!
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    Differentiating logarithmic functions

    Homework Statement Differentiate the following: y = e4x/x2+1 2. The attempt at a solution I know you have to use quotient rule here. so I wrote out (x2+1)* d/dx e4x) - d/dx (x2+1)* e4x all over (x2 + 1) 2 I have no idea how to continue on from here...how would you...
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    Optimization of a rectangle's area in two parabolas

    Actually, this is an extension on first-time calculus. Our teacher was suggesting if it was possible that by tilting the rectangle, so to speak, the maximized area would be obtained, or if it was in the question's best interest to assume a rectangle with sides parallel to the x-axis.
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    Finding the linear demand function

    Homework Statement The manager of a 120-room resort hotel has found that, on average, 50 rooms are booked when the price is $100 per night and 80 rooms are booked when the price is $80 per night. Find the demand function, assuming that it is linear, and what price should he charge to maximize...
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    Optimization of a rectangle's area in two parabolas

    Homework Statement Determine the maximum area of a rectangle formed in the region formed by the two curves y1=x2 - k y2=x2 + k Homework Equations The equations are given, I tried using k=1. so y1= x2 - 1, etc. The Attempt at a Solution Is it true that the rectangle has to be...
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    Calculus- area of a garden problem

    Homework Statement A rectangular rose garden will be surrounded by a brick wall on three sides and a fence on the fourth side. The area of the garden will be 1000m2. The cost of the brick wall is $192/m. The cost of the fencing is $48/m. Find the dimensions of the garden so that the cost is a...