help

[cobby]

How did u get the solution from the third line?

Second Derivative
Derive the original function, then derive it again

[d0minicz]

2nd derivatives arent sposed to be in methods arent they ?

[cobby]

2nd derivatives arent sposed to be in methods arent they ?

Don't think so

[Gloamglozer]

2nd derivatives arent sposed to be in methods arent they ?

Don't think so

Yeah, you're right.  They're not the in the Methods course.  Having said that, although you can use the second derivative, if you get it wrong in the exam, you will not be awarded any method marks (ie. you get 0).

[khalil]

does anyone know how it got its symbol? (d^2t/dt^2)?

[hyperblade01]

I heard it was kinda like fractions (but its not)



You multiply the d on top and the x on the bottom



There's probably a better explanation but you don't really need to know why the symbol is the symbol :p

[khalil]

Show the derivitive of 1/tan(x)  is  -cosec^2(x)

[d0minicz]

[khalil]

How do you know the last part? Is that also part of spesh?

[d0minicz]

Yeah

[TonyHem]

If you want to break down that last part
-sin^2(x)/sin^2(x) - cos^2(x)/sin^2(x)
= -1 - cos^2(x)/sin^2(x)
cos^2(x) = 1-sin^2(x)
= -1 - (1/sin^2(x) - sin^2(x)/sin^2(x))
-1-(1/sin^2(x)-1)
-1-1/sin^2(x)+1
-1/sin^2(x)
= -cosec^2(x)

[khalil]

Yeah

Which page in either Heinemann or essentials spesh book?

[TonyHem]

Yeah

Which page in either Heinemann or essentials spesh book?

It's hardly spesh.  It's just that instead of breaking things down with the limitation of using only sin and cos, tan(x) = sin(x)/cos(x) so 1/tan(x) = cos(x)/sin(x) which is cot(x). The spesh formula for it is cot^2(x)=cosec^2(x)-1
As for the page, I dunno since my essentials book is an old one n the pages r different.