Solving tan²x = 2tan(x)sin(x)

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TbbZz
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Homework Statement


tan^2x = 2tanx*sinx


Homework Equations


N/A


The Attempt at a Solution



tan^2x = 2tanx*sinx

(tan^2x)/tanx = (2tanx*sinx)/tanx

tanx = 2sinx

sinx/cosx = 2sinx

cosx = 1/2

x = [tex]pi[/tex]/3

[tex]\alpha[/tex] = [tex]pi[/tex]/3 and 5[tex]pi[/tex]/3

Not sure what I'm doing wrong.

The answer is [tex]pi[/tex]/3 and 5[tex]pi[/tex]/3 and 0, and [tex]pi[/tex]

Thanks for the assistance, I greatly appreciate it.
 
Do not simply just divide by tanx
Bring 2tanx*sinx onto the other side and then factor out the tanx

Dividing by tanx implies that tanx is never equal to zero. Which it can be in this case.
 
TbbZz said:

Homework Statement


tan^2x = 2tanx*sinx


Homework Equations


N/A


The Attempt at a Solution



tan^2x = 2tanx*sinx

(tan^2x)/tanx = (2tanx*sinx)/tanx
Either tan2(x)/tan x= 2 tan(x) sin(x)/tan(x) or tan(x)= 0.

tanx = 2sinx

sinx/cosx = 2sinx

cosx = 1/2

x = [tex]pi[/tex]/3

[tex]\alpha[/tex] = [tex]pi[/tex]/3 and 5[tex]pi[/tex]/3

Not sure what I'm doing wrong.

The answer is [tex]pi[/tex]/3 and 5[tex]pi[/tex]/3 and 0, and [tex]pi[/tex]

Thanks for the assistance, I greatly appreciate it.
 
Thanks for the help, rock.freak667 and HallsofIvy.

I got it now.