Question

Trigonometry
Step by step explanation

Answer 1

Answer:

See the explanation

Step-by-step explanation:

$\text{LHS}=1-\cot x\tan 2x$

       $=1-\dfrac{\cos x}{\sin x}\times \dfrac{\sin 2x}{\cos 2x}\\\\=1-\dfrac{\cos x}{\sin x}\times \dfrac{2\sin x\cos x}{\cos 2x}\\\\\\=1- \dfrac{2\cos^2 x}{\cos 2x}=\dfrac{\cos 2x-2\cos^2x}{\cos 2x}\\\\=\dfrac{2\cos^2x-1-2\cos^2x}{\cos 2x}\\\\=\dfrac{-1}{\cos 2x}=-\sec 2x=\text{RHS}$

Hence proved.

                               Formula used :

1.          $\sin 2x=2\sin x\cos x$
2.          $\cos2 x=2\cos^2x-1$  
3.          $\sec x=\dfrac{1}{\cos x}$

Answer 2

Step-by-step explanation:

trigonometry is the name might suggests is all

about triangle more specifically trigonomentry is about right angle triangle where one of the internal angle in 90 degree trigonometry is the system that help us to work out missing of unknown side lengths or angles in triangle