Esay Complex Number Question (2 Viewers)

[SpiralFlex]

let z= x+iy,

Im(z)= y

|z|= (sqrt)(x^2 + y^2)

y^2= x^2+y^2

x^2=0

x=0

why is this wrong? i thought you could square both sides? :\

You can but it adds another solution which covers the negative part of the imaginary axis. This is of course not valid because the modulus is a positive number.

 

[Drongoski]

You can but it adds another solution which covers the negative part of the imaginary axis. This is of course not valid because the modulus is a positive number.

Sometimes referred to as the (or 'an') extraneous solution if my memory serves me correctly.

 

[school4nerds]

guys, im trying to integrate 1/sqrt(36-x^2) and i got 1/6 times inverse sin(x/6) but apperently its only inverse sin(x/6) w/o the 1/6? can someone please explain why? D: thanks

 

[Carrotsticks]

guys, im trying to integrate 1/sqrt(36-x^2) and i got 1/6 times inverse sin(x/6) but apperently its only inverse sin(x/6) w/o the 1/6? can someone please explain why? D: thanks

Please make a separate thread to ask this question, rather than hijacking somebody else's (now dead) thread.

 

[SpiralFlex]

There is no 1/6. The only integral in the HSC that appears with 1/constant attached to it is the inverse tangent integral.

If we look at the inverse sine integral,



Compare this with the tangent integral,

 

[school4nerds]

Please make a separate thread to ask this question, rather than hijacking somebody else's (now dead) thread.

haha sorry i wouldve but im kinda noob. i dont know how to make a new thread -__-

 

[school4nerds]

There is no 1/6. The only integral in the HSC that appears with 1/constant attached to it is the inverse tangent integral.

If we look at the inverse sine integral,



Compare this with the tangent integral,

thanks!

 

[nightweaver066]

haha sorry i wouldve but im kinda noob. i dont know how to make a new thread -__-

For future use.