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Hi guys:
I have a math problem i need to solve, although it sounds easy but i just can't get the answer, can someone help me out?
Find the equation of the tangent line of y = x+3 (whole thing squared rooted) at point (6,3).
Please don't use derivatives to solve it. Thank you.=)
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just find some x values incredibly close to x=6, like x=5.999 and find the slope between that point and (6,3)
edit: oops i meant x values
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1/2 * ((6)+3)^(-1/2)
1/6?
i fail at math
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Oh that thing... Hang on I'll save you!
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The slope is 1/6, you can estimate this (since you're not using calculus) by doing what Nitrogen said, ie ( 3 - [ (5.99+3)^(1/2) ] ) / (.01) = .1667.....
Because (6,3) is 6 units in the x direction away from x = 0 and the slope is 1/6, the line will intersect the y axis one unit below (6,3), so it crosses at (0,2). Equation of line is y = (1/6)x + 2
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The only way I can think of of doing it without derivatives is something like:
1. Write the general equation for a line passing through (6,3), with the gradient as an unknown. 2. Find the points of intersection of that line and the y=sqrt(x-3) graph (the x values). Just write down the equation that x has to satisfy, it'll probably be a quadratic in x. 3. Find the values of the gradient so that the determinant of the quadratic is zero (so that the line only intersects the graph at 1 point). You'll probably get a few different values, so just look at what the line looks like for each value and pick the one that looks the best.
No idea why you'd do that, which would probably take a page or two of boring computations, when by taking the derivative you'd be able to do it in 2 lines though.
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Anyways take my advise as I'm a math tutor for my college and I just had alot of Math1A people asking me this question.
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Well he did so no derivatives, so...
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without derivatives you can only estimate where it's going , but it's really obvious after a while <_< are you trying to just grasp the logic behind it? if you understand it its essentially pointless to do it without the derivative i mean, all u can do is guess and check numbers with the derivative right?
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