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    Hello. Last question on my homework. Please give me guidance?

    I have to find the area between the curve of  y = \frac{1}{x^2} - 1

    One value of x is 4, not sure how to calculate the other. Help please?
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    The x=4 is definitely not a limit. The x-axis is where y = 0, so setting y = 0 gives you \dfrac{1}{x^2} - 1 = 0. We can rearrange this to get 1 - x^2 = 0, the roots of this equation (say x_1 and x_2, with x_1 < x_2) are the limits of integration which you use to find the area under the curve.

    Once you've found the roots of x_1 and x_2, you can evaluate \displaystyle \int_{x_1}^{x_2} \left( \dfrac{1}{x^2} - 1 \right)\, \mbox{d}x
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    4 is a limit, how do I work out my other limit? I'm struggling on that bit.
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    (Original post by Coda)
    Hello. Last question on my homework. Please give me guidance?

    I have to find the area between the curve of  y = \frac{1}{x^2} - 1

    One value of x is 4, not sure how to calculate the other. Help please?
    The area between the curve and what? Your question title says the x-axis so one of your limits will be a root of the function.
    Find the roots and sketch the curve, it will be clearer.
 
 
 
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