Recent content by rainyrabbit

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    How Do Cosine and Sine Relate to Arctan in Trigonometry?

    Why is cos(arctan x) = 1 / root(1+x^2) and sin(arctan x) = x / root(1+x^2)? I would greatly appreciate help. I'm studying for physics and this came up in one of the solutions. Thank you.
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    Linear function (difficult for me, SAT Math II level)

    Thank you very much, uart! I greatly appreciate your help.
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    Linear function (difficult for me, SAT Math II level)

    If point P(m,2m) is 5 units from the line 12x+5y=1, m could equal a. 43/11 b.-3 c.-65/22 d.5 e.3 The answer is E. Explanation given in book: - distance = abs(12(m) + 5(2m) -1) / root(144+25) = 5. >>> m=3 or -32/11 I do not understand this explanation (of course finding m from...
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    Help differential equations anyone?

    hah stupid of me thx. for your help.
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    Help differential equations anyone?

    Homework Statement Differential equation: dx/dt = 1000 + 0.10x x(0) = 1000 Solve the initial value problem for x as a function of t Section of Exponential/Logistic growth; applications (population growth) ---- Intro-level calculus Homework Equations...
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    Intro-Calculus integral problem anyone?

    Thank you for every help you have given to me. I understand now.
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    Intro-Calculus integral problem anyone?

    Homework Statement Finding Area Find the area of the region enclosed by the y-axis and the curves y=x^2 and y=(x^2+x+1)*e^(-x) The problem is from intro-level calculus and it's from Chapter 6: Differential Equations and Mathematical Modeling Section 3: Integration by parts Book...
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    Why Didn't the First Method Work for Finding the Derivative of y = x^(e^x)?

    Finding derivative question please... How should I find the derivative of y = x^(e^x)? I tried using the chain rule along with the power rule, coming out to: (e^x) (e^x) (X^(e^x - 1)) If I had took the natural log of both sides and then used implicit differentiation, I would have...
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    Creating a non-cubic polynomial

    well very many thanks I give you. Sorry, I am only at precalculus and just at the basic level, so I don't really know what happens when you multiply an equation by (x^2 + 1), but as I tried doing that it worked! The graph of the quintic equation looks very similar to my original cubic equation...
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    Creating a non-cubic polynomial

    Would you please give one or two (or more, sorry hehehe) to help me? How can you make up a polynomial that: - crosses the x-axis at -2 - just touches the x-axis at 1 ("touch" as the graph y=x^2 would only touch, not cross, the x-axis) - and is above the x-axis between -2 and 1. I know...
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