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Derivatives of inverse trig functions (1 Viewer)

cutemouse

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Hello,

For the derivatives of inverse trig functions (eg. d/dx sin-1(1-x)), can we just use the results, or do we have to derive it by going through the chain rules and stuff?

Thanks
 

Absolutezero

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If memory serves me correctly, you should just be able to to use the result.
 

Arowana21

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u wanna derive it. that is 4 unit stuff from what i can remember
 

kevinant

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It's 3U stuffs
sin y=x
dx/dy=cos x
dy/dx=1/cos x
=1/sqrt(1-x^2)
d/dx sin-1(1-x)
=-1/sqrt[1-(1-x)^2]
*use chain rule.
 

cutemouse

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Hello again,

For the domain and range for the derivatives of inverse trig functions, I've noticed that it pretty much is the range of the original inverse function, but without the 'equals' bit in the inequality. ie, if the domain of the original trig function was -1 _< x _< 1 then the derivatives' domain is -1 < x < 1

So is this always the case, or do I need to work it out?

Thanks
 

Timothy.Siu

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jm01 said:
Hello again,

For the domain and range for the derivatives of inverse trig functions, I've noticed that it pretty much is the range of the original inverse function, but without the 'equals' bit in the inequality. ie, if the domain of the original trig function was -1 _< x _< 1 then the derivatives' domain is -1 < x < 1

So is this always the case, or do I need to work it out?

Thanks
because u cant differentiate the end of a line, theres no tangent there...basically
 

cutemouse

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So is that always the case (with the domain), or can it differ?
 

Trebla

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The derivative of sin-1x and cos-1x (excludes tan-1x) is UNDEFINED at |x| = 1, as in theory a tangent to those points would be virtually vertical.
 

Timothy.Siu

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also, umm theres another reason...

y=sin-1x
y'=1/sqrt(1-x2)

y' would be undefined if x=+-1
but its because yeah u just cant different the end of a line.
 

cutemouse

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Yeah... so can I always 'assume' that if the domain of the derivative exclude the equals equality sign for the given function, but is the same values?
 

Timothy.Siu

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jm01 said:
Yeah... so can I always 'assume' that if the domain of the derivative exclude the equals equality sign for the given function, but is the same values?
yes for inverse sin and cos
 

cutemouse

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Hello,

I have one more question.

Find the derivative of tan(sin-1x)

Thanks for all those helping me.
 

Trebla

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jm01 said:
Hello,

I have one more question.

Find the derivative of tan(sin-1x)

Thanks for all those helping me.
d(tan(sin-1x)/dx = sec²(sin-1x) / √(1 - x²)
 

cutemouse

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Thanks for that... Just wondering, how do you get the denominator?

Thanks
 

Timothy.Siu

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jm01 said:
Thanks for that... Just wondering, how do you get the denominator?

Thanks
seems like derivative of sin-1x from chain rule or sometihng
actually it is.
 

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