easy integral (1 Viewer)

richz

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dunno cbb looking at the standard integral sheet...

edit: mite as well its sin^-1 (x/2) +c
 

KFunk

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integral of 1/(sqrt(4-x^2))

let x = 2sinθ ---> dx = 2cosθdθ

&int; dx/&radic;(4-x<sup>2</sup>)
= &int; 2cos&theta;/&radic;(4[1-sin<sup>2</sup>&theta;]) d&theta;
= &int; 2cos&theta;/&radic;[4cos<sup>2</sup>&theta;] d&theta;
= &int; 1 d&theta;
= &theta;

since x = 2sin&theta;
x/2 = sin&theta;
&theta; = sin<sup>-1</sup>(x/2)

therefore &int; dx/&radic;(4-x<sup>2</sup>) = sin<sup>-1</sup>(x/2)
 

thunderdax

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Haven't you done inverse trig functions yet? Because this is almost the easiest question you can get.
 

rama_v

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See the standard integral is 1/sqrt[a^2-x^2] = sin^-1 (x/a)
In this instance:
1/sqrt[4-x^2] , a= 2 so therefore the integral is sin^-1(x/2)
 

rama_v

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SaHbEeWaH said:
and, isn't it abit late to be doing these questions
like 1 year
Not really, we only did inverse trig a few weeks ago...Different schools do teh topics in different order, and a lot of it depends on what u do in 2 unit...
 

Pace_T

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i think he's referring to the thread starter's hsc finish date - 2004
hehe

EDIT: the loading up page showed ur reply after mine lol!!
 
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