How do you prove $\frac{tan (2 x)}{tan x} = 2$ $tan (2x)/tan x=2$ ?

Question

How do you prove $\frac{tan (2 x)}{tan x} = 2$ $tan (2x)/tan x=2$ ?

1 Answer

Related questions

What does it mean to prove a trigonometric identity?
How do you prove $csc θ \times tan θ = sec θ$ $\csc \theta \times \tan \theta = \sec \theta$ ?
How do you prove $(1 - {cos}^{2} x) (1 + {cot}^{2} x) = 1$ $(1-\cos^2 x)(1+\cot^2 x) = 1$ ?
How do you show that $2 sin x cos x = sin 2 x$ $2 \sin x \cos x = \sin 2x$ ? is true for $\frac{5 π}{6}$ $(5pi)/6$ ?
How do you prove that $sec x cot x = csc x$ $sec xcot x = csc x$ ?
How do you prove that $cos 2 x (1 + tan 2 x) = 1$ $cos 2x(1 + tan 2x) = 1$ ?
How do you prove that $\frac{2 sin x}{sec x (cos 4 x - sin 4 x)} = tan 2 x$ $(2sinx)/[secx(cos4x-sin4x)]=tan2x$ ?
How do you verify the identity: $- cot x = \frac{sin 3 x + sin x}{cos 3 x - cos x}$ $-cotx =(sin3x+sinx)/(cos3x-cosx)$ ?
How do you prove that $\frac{tan x + cos x}{1 + sin x} = sec x$ $(tanx+cosx)/(1+sinx)=secx$ ?
How do you prove the identity $\frac{sin x - cos x}{sin x + cos x} = \frac{2 {sin}^{2} x - 1}{1 + 2 sin x cos x}$ $(sinx - cosx)/(sinx + cosx) = (2sin^2x-1)/(1+2sinxcosx)$ ?

Impact of this question

2288 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2015-11-10T01:58:47

Prove $tan 2 \frac{x}{tan x} = 2$ $tan 2x/(tan x) = 2$

Ans: Wrong equation.

Explanation:

This trig equation is wrong.
Example: $x = \frac{π}{4}$ $x = pi/4$ --> tan x = 1 --> $tan 2 x = tan (\frac{π}{2}) =$ $tan 2x = tan (pi/2) =$ infinity.
Another proof by using trig identity.
$tan 2 x = \frac{2 tan x}{1 - {tan}^{2} x}$ $tan 2x = (2tan x)/(1 - tan^2 x)$

$\frac{tan 2 x}{tan x} = \frac{2}{1 - {tan}^{2} x}$ $(tan 2x)/(tan x) = 2/(1 -tan^2 x)$
So, the expression omits the quantity: $(1 - {tan}^{2} x)$ $(1 - tan^2 x)$

Science

Math

Humanities

... and beyond

How do you prove $\frac{tan (2 x)}{tan x} = 2$ $tan (2x)/tan x=2$ ?

1 Answer

Explanation:

Related questions

Impact of this question

Science

Math

Humanities

... and beyond

How do you prove tan (2x)/tan x=2tan(2x)tanx=2tan (2x)/tan x=2?

1 Answer

Explanation:

Related questions

Impact of this question

How do you prove $\frac{tan (2 x)}{tan x} = 2$ $tan (2x)/tan x=2$ ?