Solve the equation: cos x=-root of 2/2

Solve the equation: $\mathrm{cos}$ x=-root of 2/2
You can still ask an expert for help

• Questions are typically answered in as fast as 30 minutes

Solve your problem for the price of one coffee

• Math expert for every subject
• Pay only if we can solve it

lloviznennj
$\mathrm{cos}x=-\sqrt{2/2};$
$х=±\mathrm{arccos}\left(-\sqrt{2/2}\right)+2\pi k,k\in Z;$
$x=±\left(\pi -\mathrm{arccos}\left(\sqrt{2/2}\right)\right)+2\pi k,k\in Z;$
$x=±\left(\pi -\left(\pi /4\right)\right)+2\pi k,k\in Z;$
$x=±\left(3\pi /4\right)+2\pi k,k\in Z;$
Answer.$±\left(3\pi /4\right)+2\pi k,k\in Z.$