Find the best solutions to your problems with the help of IDNLearn.com. Discover reliable and timely information on any topic from our network of knowledgeable professionals.

Find the solutions to the given trig equation for 0 < x < 2π: tanx(cosx)=cosx

Sagot :

If tan(x)·cos(x) = cos(x),

then tan(x) = cos(x) / cos(x) = 1

The angles whose tangent is ' 1 ' are 45° and 225° .
[tex]0 \leq x\leq2\pi\ and\ x\neq\frac{\pi}{2}\ and\ x\neq\frac{3\pi}{2}\\\\tanx\cdot cosx=cosx\\\\tanx\cdot cosx-cosx=0\\\\cosx(tanx-1)=0\iff cosx=0\ \vee\ tanx=1\\\\x=\frac{\pi}{2}\notin D\ \vee\ x=\frac{3\pi}{2}\notin D\ \vee\ x=\frac{\pi}{4}\in D\ \vee\ x=\frac{5\pi}{4}\in D[/tex]