[LittleLucy]

Sooo confused...
given that y=sin^-1 (x)
a. state dx/dy and show that dy/dx = 1x(1-x^2)^-1/2
b. Expand (1-x^2)^-1/2 giving first 2 terms
c. find cubic approximation for sin^-1(x)
d. subsituting x=root3/2 into part c. find k if pi= k x root3

WHAAAT?

[raheem94]

(Original post by LittleLucy)
Sooo confused...
given that y=sin^-1 (x)
a. state dx/dy and show that dy/dx = 1x(1-x^2)^-1/2
b. Expand (1-x^2)^-1/2 giving first 2 terms
c. find cubic approximation for sin^-1(x)
d. subsituting x=root3/2 into part c. find k if pi= k x root3

WHAAAT?

y=sin^-1 (x)
In the above expression, take sin as the function of both sides.
Now you will get, siny=x.
Now use implicit differentiation to find dy/dx.
Then replace y in the dy/dx expression by sin^-1(x).

Can you do it till here?

[electriic_ink]

(Original post by raheem94)
y=sin^-1 (x)
Multiply both sides of the above expression by sin.
Now you will get, siny=x.
Now use implicit differentiation to find dy/dx.
Then replace y in the dy/dx expression by sin^-1(x).

Can you do it till here?

wut?

[raheem94]

(Original post by electriic_ink)
wut?

I think i should have written it as take sin as the function of both sides, right?

[electriic_ink]

(Original post by raheem94)
I think i should have written it as take sin as the function of both sides, right?

Yeah.

[raheem94]

(Original post by electriic_ink)
Yeah.

Thanks for correcting me.

Actually no one has taught me this, i self-study maths, so i often make such type of mistakes.