Use substitution to determine whether the given x-value is a solution of the equation.
Find All Solutions of a Trigonometric Equation
-$\cos 2 x = - \sqrt { 2 } , \quad x = \frac { 3 \pi } { 4 }$
A) Yes
B) $\mathrm { No }$

Question

Quizplus · Accepted Answer

The range of the cosine function is [-1, 1], and $-\sqrt{2}$ is not within this range, so there are no real solutions for $\cos 2x = -\sqrt{2}$.

Use Substitution to Determine Whether the Given X-Value Is a Solution