Please help solve... (1 Viewer)

[me12345]

(cosx)^2=tanx

Give general solution.

 

[Drongoski]

(cosx)^2=tanx

Give general solution.

Question looks deceptively simple !!

 

[gurmies]

Question looks deceptively simple !!

I couldn't agree more! I'm racking my brain here -.-

 

[EvoRevolution]

^ lol +1

 

[tommykins]

cos^4x = tan^2x
cos^4 x = sec^2x - 1
cos^6 x = 1 - cos^2x

solve that.

 

[Drongoski]

I couldn't agree more! I'm racking my brain here -.-

good on u gurmies. I thought my trig is 1st class. now I know it is not! leave it to younger & fresher brains.

 

[gurmies]

^ lol +1

Any input? xD

 

[study-freak]

If anyone can solve..
cos^2 x=tan x
1=tan x sec^2 x
1=tan x (1+tan^2 x)
tan^3 x + tan x -1=0

I just can't solve after this..

 

[gurmies]

If anyone can solve..
cos^2 x=tan x
1=tan x sec^2 x
1=tan x (1+tan^2 x)
tan^3 x + tan x -1=0

I just can't solve after this..

Exactly the same place I finished writing =(

 

[study-freak]

Can this question actually be solved?

 

[Timothy.Siu]

Can this question actually be solved?

well theres a solution.

 

[EvoRevolution]

nope can't get it

 

[study-freak]

OH I got it... I'll post it soon (I hope it's correct.)
Edit: Whoops. it was wrong... Still can't do it..

 

[lyounamu]

(cosx)^2=tanx

Give general solution.

kpi + app 34 degrees

 

[study-freak]

kpi + app 34 degrees

working??

 

[Timothy.Siu]

working??

lol, approximation of roots

 

[lyounamu]

lol, approximation of roots

ye that's what i used lollll

1 mark out of 2 plz lol

this q seems little bit retarded, doesn't get smoothly worked out.

 

[study-freak]

lol, approximation of roots

LOL....

Anyway, since I'm getting something imaginary, can someone plz correct my working...

From my previous post in this thread,
tan^3 x+tan x -1=0
Differentiating in terms of x,
3tan^2 x sec^2 x+sec^2 x=0
3tan^2 x=-1
tan^2 x=-1/3
tan x=i/root3
wth... imaginary number...

 

[lyounamu]

LOL....

Anyway, since I'm getting something imaginary, can someone plz correct my working...

From my previous post in this thread,
tan^3 x+tan x -1=0
Differentiating in terms of x,
3tan^2 x sec^2 x+sec^2 x=0
3tan^2 x=-1
tan^2 x=-1/3
tan x=i/root3
wth... imaginary number...

lol no,,, you cannot get imaginary because i clearly got some angles there.

 

[tommykins]

that just says theres no tp's or inflexion.