Inverse Functions (1 Viewer)

[ScarFace93]

can someone please find the inverse function of y=4x+1/x

answer is x+sqrt[x^2-16]all over 8, cheers

 

[shaon0]

can someone please find the inverse function of y=4x+1/x

answer is x+sqrt[x^-16]all over 8, cheers

Let x=y:
x=4y+1/y
xy=4y^2+1
4y^2-xy+1=0
y=x+-sqrt(x^2-16)/8 [Using quadratic formula]

 

[ScarFace93]

Let x=y:
x=4y+1/y
xy=4y^2+1
4y^2-xy+1=0
y=x+-sqrt(x^2-16)/8 [Using quadratic formula]

oh watta g, thanks man

 

[shaon0]

y=(4x+1)/x (x =/= 0)
x=(4y+1)/y (y=/=0)
yx=4y+1
4y-yx+1=0
y(4-x)+1=0
y(4-x)=-1
y=-1/(4-x)

that is what i got. dont think it is wrong.

Yeah, you made a mistake. 3rd line, theres no way i'm wrong.

 

[shaon0]

oh watta g, thanks man

Do you know why its plus instead of +-?

 

[ScarFace93]

Do you know why its plus instead of +-?

yeah the question is asking find the inverse f(x)=4x+1/x, for x>0, im guessing thats why the minus is ignored

 

[shaon0]

yeah the question is asking find the inverse f(x)=4x+1/x, for x>0, im guessing thats why the minus is ignored

Yeah