Question

найти значение выражения:
√128 * cos^2 7π/8 - √32.

Answer 1

8√2*(1+cos7π/4)-4√2=8√2*cos(2π-π/4)-4√2=8√2*cosπ/4-4√2=
=8√2*1/√2-4√2=8-4√2