#Inverse function

67 messages · Page 1 of 1 (latest)

opal iron
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yo so

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evaluating f^-1 (f(x)) at x=-5

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what does that mean

oblique lynx
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so like it’s a composite function and I need to put f(x) into the inverse

opal iron
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but specifically at x=-5

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so you wanna find f^-1 (f(-5))

oblique lynx
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yea

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But like I’m worried I did part a wrong

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which might affect my answer to part b

opal iron
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well we will find out

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so whats f(-5)

oblique lynx
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48

opal iron
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ok and then

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plug that into your inverse

oblique lynx
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I got 4

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3 sorry*

opal iron
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mmm hold on

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ok so

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when you had x/3 = (y+1)^2 when you calculated the inverse

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when you square root you need to square root everything

oblique lynx
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Ok

opal iron
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and then in square rooting

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you need to be careful cuz

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it could be either y+1 or -(y+1)

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we dont know which right

oblique lynx
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yea

opal iron
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but since x < 1

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we really want the left side of the inverse

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so we wanna take the - version

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so sqrt(x/3) = -(y+1)

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which gives you a slightly different inverse

oblique lynx
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Ok

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so like

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I got this

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I divided it by -1 after

opal iron
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its negative yeah

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so its -5

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perfec

oblique lynx
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thank you so much for the help!

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is it possible if I could have support with 1 more question though please? It’s to do with the range of a function

opal iron
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sure

oblique lynx
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Thanks so it’s q5b

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sorry I mean q5a*

opal iron
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ok so

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lets think of it like this

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whats the smallest we can make x^2

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whats the smallest square number

oblique lynx
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1

opal iron
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almost

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so theres actually smaller @oblique lynx

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0 is the smallest

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and then think about, as x gets bigger, does x^2 ever stop growing?

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that will tell you the biggest and smallest x^2 can be

oblique lynx
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It never stops growing

opal iron
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exactly

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so we can say that

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x^2 has upper range < infinity

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yeah?

oblique lynx
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Yea

opal iron
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and then we know x^2 is bigger or eql to 0

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so 0 <= x^2 < infty

oblique lynx
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Yea

opal iron
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thats the range

oblique lynx
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ohh okay