Question

what is cos 3pie/4

Answer 1

-1/sqrt(2)

Answer 2

cos 3 pie/4 =cos pie-pie/4 =-cos pie/4=-1/root(2)

Answer 3

-√(2) / 2

Answer 4

\[cos\theta = \frac{A}{H}\]\[cos{\frac{3\pi}{4}}=-cos{\frac{\pi}{4}}\]\[=-\frac{1}{\sqrt{2}}\]\[=-\frac{\sqrt{2}}{2}\]