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    idk how to do this question plz help

    x=2cot(t)
    y=2sin^2(t)

    find y=f(x)

    i got this far:

    sin^2(t) + cos^2(t) = 1

    y/2 = sin^2(t)

    x^2/4 + 1 = 2/y
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    (Original post by awijdijwajiodji)
    idk how to do this question plz help

    x=2cot(t)
    y=2sin^2(t)

    find y=f(x)

    i got this far:

    sin^2(t) + cos^2(t) = 1

    y/2 = sin^2(t)

    x^2/4 + 1 = 2/y
    If x=2cot t then x²=4cot²t and you can rearrange for cos²t using cot=cos/sin
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    (Original post by MR1999)
    If x=2cot t then x²=4cot²t and you can rearrange for cos²t using cot=cos/sin
    i did that
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    (Original post by awijdijwajiodji)
    idk how to do this question plz help

    x=2cot(t)
    y=2sin^2(t)

    find y=f(x)

    i got this far:

    sin^2(t) + cos^2(t) = 1

    y/2 = sin^2(t)

    x^2/4 + 1 = 2/y
    You're done. Just rearrange for y
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    x=2cot(t)
    y=2sin^2(t)

    This means x=2cos(t)/sin(t) --> x^2 = 4cos^2(t) / sin^2(t).

    Now play around and use the Pythagorean identity.
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    (Original post by thekidwhogames)
    x=2cot(t)
    y=2sin^2(t)

    This means x=2cos(t)/sin(t) --> x^2 = 4cos^2(t) / sin^2(t).

    Now play around and use the Pythagorean identity.
    and how do i do that

    thats literally all i was asking, you can even see ive got that far
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    bump
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    (Original post by awijdijwajiodji)
    idk how to do this question plz help

    x=2cot(t)
    y=2sin^2(t)

    find y=f(x)

    i got this far:

    sin^2(t) + cos^2(t) = 1

    y/2 = sin^2(t)

    x^2/4 + 1 = 2/y
    You have to multiply by y then divide by (x^2/4+1) to get it in the form y=f(x)
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    (Original post by awijdijwajiodji)
    and how do i do that

    thats literally all i was asking, you can even see ive got that far
    x=2cot(t)
    y=2sin^2(t)

    x = 2cos(t)/sin(t) --> x^2 = 4cos^2(t)/sin^2(T)

    y=2sin^2(t) --> y/2 = sin^2(t) -- > cos^2(t) = 1-y/2 --> 4cos^2(t) = 4-2y.

    So...?
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    (Original post by psc---maths)
    You have to multiply by y then divide by (x^2/4+1) to get it in the form y=f(x)
    where the hell did this +1 come from

    i got y = 8/x^2 +2
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    (Original post by awijdijwajiodji)
    x^2/4 + 1 = 2/y
    Now just make y the subject.
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    (Original post by awijdijwajiodji)
    idk how to do this question plz help

    x=2cot(t)
    y=2sin^2(t)

    find y=f(x)

    i got this far:

    sin^2(t) + cos^2(t) = 1

    y/2 = sin^2(t)

    x^2/4 + 1 = 2/y
    You have this

    2/y = x^2/4 + 1

    Multiplying by y gives us

    2 = yx^2/4 + y

    Which factorises as

    2 = y(x^2/4 + 1)

    So we can divide by (x^2/4 +1) to find y in terms of x
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    (Original post by RDKGames)
    Now just make y the subject.
    idk why i keep trying and ive got this


    y=2/1+x^2/4

    and then i times the top by 4 to get rid of the 4 so i get:

    8/1+x^2
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    (Original post by awijdijwajiodji)
    idk why i keep trying and ive got this


    y=2/1+x^2/4

    and then i times the top by 4 to get rid of the 4 so i get:

    8/1+x^2
    You forgot to multiply the 1 by 4
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    (Original post by awijdijwajiodji)
    idk why i keep trying and ive got this


    y=2/1+x^2/4

    and then i times the top by 4 to get rid of the 4 so i get:

    8/1+x^2
    Pretty much correct, but that 1 turns into a 4 in the denominator. It doesnt stay.
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    (Original post by psc---maths)
    You forgot to multiply the 1 by 4

    why would i do that, i noticed that too but i cant figure out why i should do that
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    (Original post by awijdijwajiodji)
    why would i do that, i noticed that too but i cant figure out why i should do that
    y=2 / (x^2/4 1)

    That is

    y=(2 / (x^2/4 1)) * (4 / 4) (#)

    Now,

    2*4 =8

    And

    (X^2/4 1) * 4 = 4x^2/4 4 = x^2 4

    So, from (#)


    y=8 / (x^2 4)
    Posted on the TSR App. Download from Apple or Google Play
 
 
 
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